diff --git a/CHANGELOG.md b/CHANGELOG.md
index 10b3aa25..eda06eff 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,13 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 Previous releases are documented in [github releases](https://github.com/oscarotero/Gettext/releases)
 
+## [5.7.0] - 2021-07-27
+### Added
+- StrictPoLoader, a stricter PO loader more aligned with the syntax of the GNU gettext tooling [#282].
+- Previous attributes (msgctxt, msgid, msgid_plural) to the Translation class and the PO generator [#282].
+### Changed
+- Minor performance improvements to the Translations class [#282].
+
 ## [5.6.1] - 2021-12-04
 ### Fixed
 - PHP 8.1 support [#278].
@@ -112,7 +119,9 @@ Previous releases are documented in [github releases](https://github.com/oscarot
 [#265]: https://github.com/php-gettext/Gettext/issues/265
 [#276]: https://github.com/php-gettext/Gettext/issues/276
 [#278]: https://github.com/php-gettext/Gettext/issues/278
+[#282]: https://github.com/php-gettext/Gettext/issues/282
 
+[5.7.0]: https://github.com/php-gettext/Gettext/compare/v5.6.1...v5.7.0
 [5.6.1]: https://github.com/php-gettext/Gettext/compare/v5.6.0...v5.6.1
 [5.6.0]: https://github.com/php-gettext/Gettext/compare/v5.5.4...v5.6.0
 [5.5.4]: https://github.com/php-gettext/Gettext/compare/v5.5.3...v5.5.4
diff --git a/README.md b/README.md
index 0d181c9a..cb6eb9ce 100644
--- a/README.md
+++ b/README.md
@@ -94,7 +94,7 @@ $translations->setDomain('my-blog');
 
 ## Loaders
 
-The loaders allows to get gettext values from any format. For example, to load a .po file:
+The loaders allow to get gettext values from multiple formats. For example, to load a .po file:
 
 ```php
 use Gettext\Loader\PoLoader;
@@ -109,10 +109,39 @@ $string = file_get_contents('locales2/en.po');
 $translations = $loader->loadString($string);
 ```
 
+As of version 5.7.0, a `StrictPoLoader` has been included, with a parser more aligned to the GNU gettext tooling with the same expectations and failures (see the tests for more details).
+- It will fail with an exception when there's anything wrong with the syntax, and display the reason together with the line/byte where it happened.
+- It might also emit useful warnings, e.g. when there are more/less plural translations than needed, missing translation header, dangling comments not associated with any translation, etc.
+- Due to its strictness and speed (about 50% slower than the `PoLoader`), it might be interesting to be used as a kind of `.po` linter in a build system.
+- It also implements the previous translation comment (e.g. `#| msgid "previous"`) and extra escapes (16-bit unicode `\u`, 32-bit unicode `\U`, hexadecimal `\xFF` and octal `\77`).
+
+The usage is basically the same as the `PoLoader`:
+
+```php
+use Gettext\Loader\StrictPoLoader;
+
+$loader = new StrictPoLoader();
+
+//From a file
+$translations = $loader->loadFile('locales/en.po');
+
+//From a string
+$string = file_get_contents('locales2/en.po');
+$translations = $loader->loadString($string);
+
+//Display error messages using "at line X column Y" instead of "at byte X"
+$loader->displayErrorLine = true;
+//Throw an exception when a warning happens
+$loader->throwOnWarning = true;
+//Retrieve the warnings
+$loader->getWarnings();
+```
+
 This package includes the following loaders:
 
 - `MoLoader`
 - `PoLoader`
+- `StrictPoLoader`
 
 And you can install other formats with loaders and generators:
 
diff --git a/src/Generator/PoGenerator.php b/src/Generator/PoGenerator.php
index 0dc8de8f..000c1a6a 100644
--- a/src/Generator/PoGenerator.php
+++ b/src/Generator/PoGenerator.php
@@ -65,6 +65,18 @@ public function generateString(Translations $translations): string
 
             $prefix = $translation->isDisabled() ? '#~ ' : '';
 
+            if ($context = $translation->getPreviousContext()) {
+                $lines[] = sprintf('%s#| msgctxt %s', $prefix, self::encode($context));
+            }
+
+            if ($original = $translation->getPreviousOriginal()) {
+                $lines[] = sprintf('%s#| msgid %s', $prefix, self::encode($original));
+            }
+
+            if ($plural = $translation->getPreviousPlural()) {
+                $lines[] = sprintf('%s#| msgid_plural %s', $prefix, self::encode($plural));
+            }
+
             if ($context = $translation->getContext()) {
                 $lines[] = sprintf('%smsgctxt %s', $prefix, self::encode($context));
             }
diff --git a/src/Loader/MoLoader.php b/src/Loader/MoLoader.php
index fe3e09a7..c5079048 100644
--- a/src/Loader/MoLoader.php
+++ b/src/Loader/MoLoader.php
@@ -4,7 +4,6 @@
 namespace Gettext\Loader;
 
 use Exception;
-use Gettext\Translation;
 use Gettext\Translations;
 
 /**
diff --git a/src/Loader/StrictPoLoader.php b/src/Loader/StrictPoLoader.php
new file mode 100644
index 00000000..fd80b4f8
--- /dev/null
+++ b/src/Loader/StrictPoLoader.php
@@ -0,0 +1,485 @@
+<?php
+declare(strict_types = 1);
+
+namespace Gettext\Loader;
+
+use Exception;
+use Gettext\Translation;
+use Gettext\Translations;
+
+/**
+ * Class to load a PO file following the same rules of the GNU gettext tools.
+ */
+final class StrictPoLoader extends Loader
+{
+    /** @var bool */
+    public $throwOnWarning = false;
+    /** @var bool */
+    public $displayErrorLine = false;
+
+    /** @var Translations */
+    private $translations;
+    /** @var Translation */
+    private $translation;
+    /** @var Translation|null */
+    private $header;
+    /** @var string */
+    private $data;
+    /** @var int */
+    private $position;
+    /** @var int|null */
+    private $pluralCount;
+    /** @var bool */
+    private $inPreviousPart;
+    /** @var string[] */
+    private $warnings = [];
+    /** @var bool */
+    private $isDisabled;
+    /** @var bool */
+    private $displayLineColumn;
+
+    /**
+     * Generates a Translations object from a .po based string
+     */
+    public function loadString(string $data, Translations $translations = null): Translations
+    {
+        $this->data = $data;
+        $this->position = 0;
+        $this->translations = parent::loadString($this->data, $translations);
+        $this->header = $this->translations->find(null, '');
+        $this->pluralCount = $this->translations->getHeaders()->getPluralForm()[0] ?? null;
+        $this->warnings = [];
+        for ($length = strlen($this->data); $this->newEntry(); $this->saveEntry()) {
+            for ($hasComment = false; $this->readComment(); $hasComment = true);
+            $this->readWhitespace();
+            // End of data
+            if ($this->position >= $length) {
+                if ($hasComment) {
+                    $this->addWarning("Comment ignored at the end of the string{$this->getErrorPosition()}");
+                }
+                break;
+            }
+            $this->readContext();
+            $this->readOriginal();
+            if ($this->translations->has($this->translation)) {
+                throw new Exception("Duplicated entry{$this->getErrorPosition()}");
+            }
+            if (!$this->readPlural()) {
+                $this->readTranslation();
+                continue;
+            }
+            for ($count = 0; $this->readPluralTranslation(!$count); ++$count);
+            $count !== ($this->pluralCount ?? $count) && $this->addWarning("The translation has {$count} plural "
+                . "forms, while the header expects {$this->pluralCount}{$this->getErrorPosition()}");
+        }
+        if (!$this->header) {
+            $this->addWarning("The loaded string has no header translation{$this->getErrorPosition()}");
+        }
+
+        return $this->translations;
+    }
+
+    /**
+     * Retrieves the collected warnings
+     * @return string[]
+     */
+    public function getWarnings(): array
+    {
+        return $this->warnings;
+    }
+
+    /**
+     * Prepares to parse a new translation
+     */
+    private function newEntry(): Translation
+    {
+        $this->isDisabled = false;
+
+        return $this->translation = $this->createTranslation(null, '');
+    }
+
+    /**
+     * Adds the current translation to the output list
+     */
+    private function saveEntry(): void
+    {
+        if ($this->isHeader()) {
+            $this->processHeader();
+
+            return;
+        }
+        $this->translations->add($this->translation);
+    }
+
+    /**
+     * Attempts to read whitespace characters, also might skip complex comment prologs when needed
+     * @return int The position before comments started being consumed
+     */
+    private function readWhitespace(): int
+    {
+        do {
+            $this->position += strspn($this->data, " \n\r\t\v\0", $this->position);
+            $checkpoint ?? $checkpoint = $this->position;
+        } while (($this->isDisabled && $this->readString('#~')) || ($this->inPreviousPart && $this->readString('#|')));
+
+        return $checkpoint;
+    }
+
+    /**
+     * Attempts to read the exact informed string
+     */
+    private function readString(string $data): bool
+    {
+        return !substr_compare($this->data, $data, $this->position, $l = strlen($data)) && $this->position += $l;
+    }
+
+    /**
+     * Attempts to read the exact informed char
+     */
+    private function readChar(string $char): bool
+    {
+        return ($this->data[$this->position] ?? null) === $char && ++$this->position;
+    }
+
+    /**
+     * Read sequential characters that match the given character set until the length range is satisfied
+     */
+    private function readCharset(string $charset, int $min, int $max, string $name): string
+    {
+        if (($length = strspn($this->data, $charset, $this->position, $max)) < $min) {
+            throw new Exception("Expected at least {$min} occurrence of {$name} characters{$this->getErrorPosition()}");
+        }
+
+        return substr($this->data, ($this->position += $length) - $length, $length);
+    }
+
+    /**
+     * Attempts to read a standard comment string which ends with a newline
+     */
+    private function readCommentString(): string
+    {
+        $length = strcspn($this->data, "\n\r", $this->position);
+
+        return substr($this->data, ($this->position += $length) - $length, $length);
+    }
+
+    /**
+     * Attempts to read a quoted string while parsing escape sequences prefixed by \
+     */
+    private function readQuotedString(?string $context = null): string
+    {
+        $this->readWhitespace();
+        for ($data = '', $isNewPart = true, $checkpoint = null;;) {
+            if ($isNewPart && !$this->readChar('"')) {
+                // The data is over (e.g. beginning of an identifier) or perhaps there's an error
+                // Restore the checkpoint and let the next parser handle it
+                if ($checkpoint !== null) {
+                    $this->position = $checkpoint;
+                    break;
+                }
+                throw new Exception("Expected an opening quote{$this->getErrorPosition()}");
+            }
+            $isNewPart = false;
+            // Collects chars until an edge case is found
+            $length = strcspn($this->data, "\"\r\n\\", $this->position);
+            $data .= substr($this->data, $this->position, $length);
+            $this->position += $length;
+            // Check edge cases
+            switch ($this->data[$this->position++] ?? null) {
+                // End of part, saves a checkpoint and attempts to read a new part
+                case '"':
+                    $checkpoint = $this->readWhitespace();
+                    $isNewPart = true;
+                    break;
+                case '\\':
+                    $data .= $this->readEscape();
+                    break;
+                // Unexpected newline
+                case "\r":
+                case "\n":
+                    throw new Exception("Newline character must be escaped{$this->getErrorPosition()}");
+                // Unexpected end of file
+                case null:
+                    throw new Exception("Expected a closing quote{$this->getErrorPosition()}");
+            }
+        }
+        if ($context && strlen($data) && strpbrk($data[0] . $data[strlen($data) - 1], "\r\n") && !$this->isHeader()) {
+            $this->addWarning("$context cannot start nor end with a newline{$this->getErrorPosition()}");
+        }
+
+        return $data;
+    }
+
+    /**
+     * Reads escaped data
+     */
+    private function readEscape(): string
+    {
+        $aliasMap = ['from' => 'efnrtv"ab\\', 'to' => "\e\f\n\r\t\v\"\x07\x08\\"];
+        $hexDigits = '0123456789abcdefABCDEF';
+        switch ($char = $this->data[$this->position++] ?? "\0") {
+            case strpbrk($char, $aliasMap['from']) ?: '':
+                return $aliasMap['to'][strpos($aliasMap['from'], $char)];
+            case strpbrk($char, $octalDigits = '01234567'):
+                // GNU gettext fails with an octal above the signed char range
+                if (($decimal = octdec($char . $this->readCharset($octalDigits, 0, 2, 'octal'))) > 127) {
+                    throw new Exception("Octal value out of range [0, 0177]{$this->getErrorPosition()}");
+                }
+
+                return chr($decimal);
+            case 'x':
+                $value = $this->readCharset($hexDigits, 1, PHP_INT_MAX, 'hexadecimal');
+                // GNU reads all valid hexadecimal chars, but only uses the last pair
+                return hex2bin(str_pad(substr($value, -2), 2, '0', STR_PAD_LEFT));
+            case 'U':
+            case 'u':
+                // The GNU gettext is supposed to follow the escaping sequences of C
+                // Curiously it doesn't support the unicode escape
+                $value = $this->readCharset($hexDigits, 1, $digits = $char === 'u' ? 4 : 8, 'hexadecimal');
+                $value = str_pad($value, $digits, '0', STR_PAD_LEFT);
+
+                return mb_convert_encoding(hex2bin($value), 'UTF-8', 'UTF-' . ($digits * 4));
+        }
+        throw new Exception("Invalid escaped character{$this->getErrorPosition()}");
+    }
+
+    /**
+     * Attempts to read and interpret a comment
+     */
+    private function readComment(): bool
+    {
+        $this->readWhitespace();
+        if (!$this->readChar('#')) {
+            return false;
+        }
+        $type = strpbrk($this->data[$this->position] ?? '', '~|,:.') ?: '';
+        $this->position += strlen($type);
+        // Only a single space might be optionally added
+        $this->readChar(' ');
+        switch ($type) {
+            case '':
+                $data = $this->readCommentString();
+                $this->translation->getComments()->add($data);
+                break;
+            case '~':
+                if ($this->translation->getPreviousOriginal() !== null) {
+                    throw new Exception("Inconsistent use of #~{$this->getErrorPosition()}");
+                }
+                $this->translation->disable();
+                $this->isDisabled = true;
+                break;
+            case '|':
+                if ($this->translation->getPreviousOriginal() !== null) {
+                    throw new Exception('Cannot redeclare the previous comment #|, '
+                        . "ensure the definitions are in the right order{$this->getErrorPosition()}");
+                }
+                $this->inPreviousPart = true;
+                $this->translation->setPreviousContext($this->readIdentifier('msgctxt'));
+                $this->translation->setPreviousOriginal($this->readIdentifier('msgid', true));
+                $this->translation->setPreviousPlural($this->readIdentifier('msgid_plural'));
+                $this->inPreviousPart = false;
+                break;
+            case ',':
+                $data = $this->readCommentString();
+                foreach (array_map('trim', explode(',', trim($data))) as $value) {
+                    $this->translation->getFlags()->add($value);
+                }
+                break;
+            case ':':
+                $data = $this->readCommentString();
+                foreach (preg_split('/\s+/', trim($data)) as $value) {
+                    if (preg_match('/^(.+)(:(\d*))?$/U', $value, $matches)) {
+                        $line = isset($matches[3]) ? intval($matches[3]) : null;
+                        $this->translation->getReferences()->add($matches[1], $line);
+                    }
+                }
+                break;
+            case '.':
+                $data = $this->readCommentString();
+                $this->translation->getExtractedComments()->add($data);
+                break;
+        }
+
+        return true;
+    }
+
+    /**
+     * Attempts to read an identifier
+     */
+    private function readIdentifier(string $identifier, bool $throwIfNotFound = false): ?string
+    {
+        $checkpoint = $this->readWhitespace();
+        if ($this->readString($identifier)) {
+            return $this->readQuotedString($identifier);
+        }
+        if ($throwIfNotFound) {
+            throw new Exception("Expected $identifier{$this->getErrorPosition()}");
+        }
+        $this->position = $checkpoint;
+
+        return null;
+    }
+
+    /**
+     * Attempts to read the context
+     */
+    private function readContext(): bool
+    {
+        return ($data = $this->readIdentifier('msgctxt')) !== null
+            && ($this->translation = $this->translation->withContext($data));
+    }
+
+    /**
+     * Reads the original message
+     */
+    private function readOriginal(): void
+    {
+        $this->translation = $this->translation->withOriginal($this->readIdentifier('msgid', true));
+    }
+
+    /**
+     * Attempts to read the plural message
+     */
+    private function readPlural(): bool
+    {
+        return ($data = $this->readIdentifier('msgid_plural')) !== null && $this->translation->setPlural($data);
+    }
+
+    /**
+     * Reads the translation
+     */
+    private function readTranslation(): void
+    {
+        $this->readWhitespace();
+        if (!$this->readString('msgstr')) {
+            throw new Exception("Expected msgstr{$this->getErrorPosition()}");
+        }
+        $this->translation->translate($this->readQuotedString('msgstr'));
+    }
+
+    /**
+     * Attempts to read the pluralized translation
+     */
+    private function readPluralTranslation(bool $throwIfNotFound = false): bool
+    {
+        $this->readWhitespace();
+        if (!$this->readString('msgstr')) {
+            if ($throwIfNotFound) {
+                throw new Exception("Expected indexed msgstr{$this->getErrorPosition()}");
+            }
+
+            return false;
+        }
+        $this->readWhitespace();
+        if (!$this->readChar('[')) {
+            throw new Exception("Expected character \"[\"{$this->getErrorPosition()}");
+        }
+        $this->readWhitespace();
+        $index = (int) $this->readCharset('0123456789', 1, PHP_INT_MAX, 'numeric');
+        $this->readWhitespace();
+        if (!$this->readChar(']')) {
+            throw new Exception("Expected character \"]\"{$this->getErrorPosition()}");
+        }
+        $translations = $this->translation->getPluralTranslations();
+        if (($translation = $this->translation->getTranslation()) !== null) {
+            array_unshift($translations, $translation);
+        }
+        if (count($translations) !== (int) $index) {
+            throw new Exception("The msgstr has an invalid index{$this->getErrorPosition()}");
+        }
+        $data = $this->readQuotedString('msgstr');
+        $translations[] = $data;
+        $this->translation->translate(array_shift($translations));
+        $this->translation->translatePlural(...$translations);
+
+        return true;
+    }
+
+    /**
+     * Setup the current translation as the header translation
+     */
+    private function processHeader(): void
+    {
+        $this->header = $header = $this->translation;
+        if (count($description = $header->getComments()->toArray())) {
+            $this->translations->setDescription(implode("\n", $description));
+        }
+        if (count($flags = $header->getFlags()->toArray())) {
+            $this->translations->getFlags()->add(...$flags);
+        }
+        $headers = $this->translations->getHeaders();
+        if (($header->getTranslation() ?? '') !== '') {
+            foreach (self::readHeaders($header->getTranslation()) as $name => $value) {
+                $headers->set($name, $value);
+            }
+        }
+        $this->pluralCount = $headers->getPluralForm()[0] ?? null;
+        foreach (['Language', 'Plural-Forms', 'Content-Type'] as $header) {
+            if (($headers->get($header) ?? '') === '') {
+                $this->addWarning("$header header not declared or empty{$this->getErrorPosition()}");
+            }
+        }
+    }
+
+    /**
+     * Parses the translation header data into an array
+     */
+    private function readHeaders(string $data): array
+    {
+        $headers = [];
+        $name = null;
+        foreach (explode("\n", $data) as $line) {
+            // Checks if it is a header definition line.
+            // Useful for distinguishing between header definitions and possible continuations of a header entry.
+            if (preg_match('/^[\w-]+:/', $line)) {
+                [$name, $value] = explode(':', $line, 2);
+                if (isset($headers[$name])) {
+                    $this->addWarning("Header already defined{$this->getErrorPosition()}");
+                }
+                $headers[$name] = trim($value);
+                continue;
+            }
+            // Data without a definition
+            if ($name === null) {
+                $this->addWarning("Malformed header name{$this->getErrorPosition()}");
+                continue;
+            }
+            $headers[$name] .= $line;
+        }
+
+        return $headers;
+    }
+
+    /**
+     * Adds a warning
+     */
+    private function addWarning(string $message): void
+    {
+        if ($this->throwOnWarning) {
+            throw new Exception($message);
+        }
+        $this->warnings[] = $message;
+    }
+
+    /**
+     * Checks whether the current translation is a header translation
+     */
+    private function isHeader(): bool
+    {
+        return $this->translation->getOriginal() === '' && $this->translation->getContext() === null;
+    }
+
+    /**
+     * Retrieves the position where an error was detected
+     */
+    private function getErrorPosition(): string
+    {
+        if ($this->displayErrorLine) {
+            $pieces = preg_split("/\\r\\n|\\n\\r|\\n|\\r/", substr($this->data, 0, $this->position));
+            $line = count($pieces);
+            $column = strlen(end($pieces));
+            return " at line {$line} column {$column}";
+        }
+        return " at byte {$this->position}";
+    }
+}
diff --git a/src/Scanner/CodeScanner.php b/src/Scanner/CodeScanner.php
index e854dd7e..d01caf3b 100644
--- a/src/Scanner/CodeScanner.php
+++ b/src/Scanner/CodeScanner.php
@@ -5,7 +5,6 @@
 
 use Exception;
 use Gettext\Translation;
-use Gettext\Translations;
 
 /**
  * Base class with common functions to scan files with code and get gettext translations.
diff --git a/src/Translation.php b/src/Translation.php
index 45aa0a61..6f590c42 100644
--- a/src/Translation.php
+++ b/src/Translation.php
@@ -19,6 +19,9 @@ class Translation
     protected $flags;
     protected $comments;
     protected $extractedComments;
+    protected $previousContext;
+    protected $previousOriginal;
+    protected $previousPlural;
 
     public static function create(?string $context, string $original): Translation
     {
@@ -64,6 +67,9 @@ public function toArray(): array
             'plural' => $this->plural,
             'pluralTranslations' => $this->pluralTranslations,
             'disabled' => $this->disabled,
+            'previousContext' => $this->previousContext,
+            'previousOriginal' => $this->previousOriginal,
+            'previousPlural' => $this->previousPlural,
             'references' => $this->getReferences()->toArray(),
             'flags' => $this->getFlags()->toArray(),
             'comments' => $this->getComments()->toArray(),
@@ -116,6 +122,42 @@ public function getPlural(): ?string
         return $this->plural;
     }
 
+    public function setPreviousOriginal(?string $previousOriginal): self
+    {
+        $this->previousOriginal = $previousOriginal;
+
+        return $this;
+    }
+
+    public function getPreviousOriginal(): ?string
+    {
+        return $this->previousOriginal;
+    }
+
+    public function setPreviousContext(?string $previousContext): self
+    {
+        $this->previousContext = $previousContext;
+
+        return $this;
+    }
+
+    public function getPreviousContext(): ?string
+    {
+        return $this->previousContext;
+    }
+
+    public function setPreviousPlural(?string $previousPlural): self
+    {
+        $this->previousPlural = $previousPlural;
+
+        return $this;
+    }
+
+    public function getPreviousPlural(): ?string
+    {
+        return $this->previousPlural;
+    }
+
     public function disable(bool $disabled = true): self
     {
         $this->disabled = $disabled;
@@ -225,6 +267,18 @@ public function mergeWith(Translation $translation, int $strategy = 0): Translat
             $merged->plural = $translation->plural;
         }
 
+        if (!$merged->previousContext || ($translation->previousContext && $override)) {
+            $merged->previousContext = $translation->previousContext;
+        }
+
+        if (!$merged->previousOriginal || ($translation->previousOriginal && $override)) {
+            $merged->previousOriginal = $translation->previousOriginal;
+        }
+
+        if (!$merged->previousPlural || ($translation->previousPlural && $override)) {
+            $merged->previousPlural = $translation->previousPlural;
+        }
+
         if (empty($merged->pluralTranslations) || (!empty($translation->pluralTranslations) && $override)) {
             $merged->pluralTranslations = $translation->pluralTranslations;
         }
diff --git a/src/Translations.php b/src/Translations.php
index eed33979..f0a5964f 100644
--- a/src/Translations.php
+++ b/src/Translations.php
@@ -125,11 +125,7 @@ public function addOrMerge(Translation $translation, int $mergeStrategy = 0): Tr
 
     public function remove(Translation $translation): self
     {
-        $key = array_search($translation, $this->translations);
-
-        if ($key !== false) {
-            unset($this->translations[$key]);
-        }
+        unset($this->translations[$translation->getId()]);
 
         return $this;
     }
@@ -168,13 +164,12 @@ public function getLanguage(): ?string
 
     public function find(?string $context, string $original): ?Translation
     {
-        foreach ($this->translations as $translation) {
-            if ($translation->getContext() === $context && $translation->getOriginal() === $original) {
-                return $translation;
-            }
-        }
+        return $this->translations[(Translation::create($context, $original))->getId()] ?? null;
+    }
 
-        return null;
+    public function has(Translation $translation): bool
+    {
+        return (bool) ($this->translations[$translation->getId()] ?? false);
     }
 
     public function mergeWith(Translations $translations, int $strategy = 0): Translations
diff --git a/tests/BasePoLoaderTestCase.php b/tests/BasePoLoaderTestCase.php
new file mode 100644
index 00000000..76cdac63
--- /dev/null
+++ b/tests/BasePoLoaderTestCase.php
@@ -0,0 +1,291 @@
+<?php
+declare(strict_types = 1);
+
+namespace Gettext\Tests;
+
+use Gettext\Loader\Loader;
+use Gettext\Translation;
+use PHPUnit\Framework\TestCase;
+
+abstract class BasePoLoaderTestCase extends TestCase
+{
+    abstract protected function createPoLoader(): Loader;
+
+    public function testPoLoader()
+    {
+        $loader = $this->createPoLoader();
+        $translations = $loader->loadFile(__DIR__.'/assets/translations.po');
+
+        $description = $translations->getDescription();
+        $this->assertSame(
+            <<<'EOT'
+SOME DESCRIPTIVE TITLE
+Copyright (C) YEAR Free Software Foundation, Inc.
+This file is distributed under the same license as the PACKAGE package.
+FIRST AUTHOR <EMAIL@ADDRESS>, YEAR.
+EOT
+        ,
+            $description
+        );
+
+        $this->assertSame(['fuzzy'], $translations->getFlags()->toArray());
+
+        $this->assertCount(14, $translations);
+
+        $array = $translations->getTranslations();
+
+        $this->translation1(array_shift($array));
+        $this->translation2(array_shift($array));
+        $this->translation3(array_shift($array));
+        $this->translation4(array_shift($array));
+        $this->translation5(array_shift($array));
+        $this->translation6(array_shift($array));
+        $this->translation7(array_shift($array));
+        $this->translation8(array_shift($array));
+        $this->translation9(array_shift($array));
+        $this->translation10(array_shift($array));
+        $this->translation11(array_shift($array));
+        $this->translation12(array_shift($array));
+        $this->translation13(array_shift($array));
+        $this->translation14(array_shift($array));
+
+        $headers = $translations->getHeaders()->toArray();
+
+        $this->assertCount(12, $headers);
+
+        $this->assertSame('text/plain; charset=UTF-8', $headers['Content-Type']);
+        $this->assertSame('8bit', $headers['Content-Transfer-Encoding']);
+        $this->assertSame('', $headers['POT-Creation-Date']);
+        $this->assertSame('', $headers['PO-Revision-Date']);
+        $this->assertSame('', $headers['Last-Translator']);
+        $this->assertSame('', $headers['Language-Team']);
+        $this->assertSame('1.0', $headers['MIME-Version']);
+        $this->assertSame('bs', $headers['Language']);
+        $this->assertSame(
+            'nplurals=3; plural=(n%10==1 && n%100!=11 ? 0 : n%10>=2 && n%10<=4 && (n%100<10 || n%100>=20) ? 1 : 2);',
+            $headers['Plural-Forms']
+        );
+        $this->assertSame('Poedit 1.6.5', $headers['X-Generator']);
+        $this->assertSame('gettext generator test', $headers['Project-Id-Version']);
+        $this->assertSame('testingdomain', $headers['X-Domain']);
+
+        $this->assertSame('testingdomain', $translations->getDomain());
+        $this->assertSame('bs', $translations->getLanguage());
+    }
+
+    private function translation1(Translation $translation)
+    {
+        $this->assertSame(
+            'Ensure this value has at least %(limit_value)d character (it has %sd).',
+            $translation->getOriginal()
+        );
+        $this->assertSame(
+            'Ensure this value has at least %(limit_value)d characters (it has %sd).',
+            $translation->getPlural()
+        );
+        $this->assertSame('', $translation->getTranslation());
+        $this->assertSame(['', ''], $translation->getPluralTranslations());
+    }
+
+    private function translation2(Translation $translation)
+    {
+        $this->assertSame(
+            'Ensure this value has at most %(limit_value)d character (it has %sd).',
+            $translation->getOriginal()
+        );
+        $this->assertSame(
+            'Ensure this value has at most %(limit_value)d characters (it has %sd).',
+            $translation->getPlural()
+        );
+        $this->assertSame('', $translation->getTranslation());
+        $this->assertSame(['', ''], $translation->getPluralTranslations());
+    }
+
+    private function translation3(Translation $translation)
+    {
+        $this->assertSame('%ss must be unique for %ss %ss.', $translation->getOriginal());
+        $this->assertNull($translation->getPlural());
+        $this->assertSame('%ss mora da bude jedinstven za %ss %ss.', $translation->getTranslation());
+        $this->assertCount(0, $translation->getPluralTranslations());
+    }
+
+    private function translation4(Translation $translation)
+    {
+        $this->assertSame('and', $translation->getOriginal());
+        $this->assertNull($translation->getPlural());
+        $this->assertSame('i', $translation->getTranslation());
+        $this->assertCount(0, $translation->getPluralTranslations());
+        $this->assertSame(['c-format'], $translation->getFlags()->toArray());
+    }
+
+    private function translation5(Translation $translation)
+    {
+        $this->assertSame('Value %sr is not a valid choice.', $translation->getOriginal());
+        $this->assertNull($translation->getPlural());
+        $this->assertSame('', $translation->getTranslation());
+        $this->assertCount(0, $translation->getPluralTranslations());
+        $this->assertSame(['This is a extracted comment'], $translation->getExtractedComments()->toArray());
+    }
+
+    private function translation6(Translation $translation)
+    {
+        $this->assertSame('This field cannot be null.', $translation->getOriginal());
+        $this->assertNull($translation->getPlural());
+        $this->assertSame('Ovo polje ne može ostati prazno.', $translation->getTranslation());
+        $this->assertCount(0, $translation->getPluralTranslations());
+        $this->assertCount(1, $translation->getReferences());
+        $this->assertSame(['C:/Users/Me/Documents/foo2.php' => [1]], $translation->getReferences()->toArray());
+    }
+
+    private function translation7(Translation $translation)
+    {
+        $this->assertSame('This field cannot be blank.', $translation->getOriginal());
+        $this->assertNull($translation->getPlural());
+        $this->assertSame('Ovo polje ne može biti prazno.', $translation->getTranslation());
+        $this->assertCount(0, $translation->getPluralTranslations());
+        $this->assertCount(1, $translation->getReferences());
+        $this->assertSame(['C:/Users/Me/Documents/foo1.php' => []], $translation->getReferences()->toArray());
+    }
+
+    private function translation8(Translation $translation)
+    {
+        $this->assertSame('Field of type: %ss', $translation->getOriginal());
+        $this->assertNull($translation->getPlural());
+        $this->assertSame('Polje tipa: %ss', $translation->getTranslation());
+        $this->assertCount(0, $translation->getPluralTranslations());
+        $this->assertCount(2, $translation->getReferences());
+        $this->assertSame(
+            [
+                'attributes/address/composer.php' => [8],
+                'attributes/address/form.php' => [7],
+            ],
+            $translation->getReferences()->toArray()
+        );
+    }
+
+    private function translation9(Translation $translation)
+    {
+        $this->assertSame('Integer', $translation->getOriginal());
+        $this->assertNull($translation->getPlural());
+        $this->assertSame('Cijeo broj', $translation->getTranslation());
+        $this->assertCount(0, $translation->getPluralTranslations());
+        $this->assertCount(0, $translation->getReferences());
+        $this->assertCount(1, $translation->getComments());
+        $this->assertSame(['a simple line comment is above'], $translation->getComments()->toArray());
+    }
+
+    private function translation10(Translation $translation)
+    {
+        $this->assertSame('{test1}', $translation->getOriginal());
+        $this->assertNull($translation->getPlural());
+        $this->assertSame("test1\n<div>\n test2\n</div>\ntest3", $translation->getTranslation());
+        $this->assertCount(0, $translation->getPluralTranslations());
+        $this->assertCount(0, $translation->getComments());
+        $this->assertCount(3, $translation->getReferences());
+        $this->assertSame(
+            [
+                '/var/www/test/test.php' => [96, 97],
+                '/var/www/test/test2.php' => [98],
+            ],
+            $translation->getReferences()->toArray()
+        );
+    }
+
+    private function translation11(Translation $translation)
+    {
+        $this->assertSame('{test2}', $translation->getOriginal());
+        $this->assertNull($translation->getPlural());
+        $this->assertSame("test1\n<div>\n test2\n</div>\ntest3", $translation->getTranslation());
+        $this->assertCount(0, $translation->getPluralTranslations());
+        $this->assertCount(0, $translation->getComments());
+        $this->assertCount(1, $translation->getReferences());
+        $this->assertSame(
+            ['/var/www/test/test.php' => [96]],
+            $translation->getReferences()->toArray()
+        );
+    }
+
+    private function translation12(Translation $translation)
+    {
+        $this->assertSame('Multibyte test', $translation->getOriginal());
+        $this->assertNull($translation->getPlural());
+        $this->assertSame('日本人は日本で話される言語です！', $translation->getTranslation());
+        $this->assertCount(0, $translation->getPluralTranslations());
+        $this->assertCount(0, $translation->getComments());
+        $this->assertCount(0, $translation->getReferences());
+    }
+
+    private function translation13(Translation $translation)
+    {
+        $this->assertSame('Tabulation test', $translation->getOriginal());
+        $this->assertNull($translation->getPlural());
+        $this->assertSame("FIELD\tFIELD", $translation->getTranslation());
+        $this->assertCount(0, $translation->getPluralTranslations());
+        $this->assertCount(0, $translation->getComments());
+        $this->assertCount(0, $translation->getReferences());
+    }
+
+    private function translation14(Translation $translation)
+    {
+        $this->assertSame('%s has been added to your cart.', $translation->getOriginal());
+        $this->assertSame('%s have been added to your cart.', $translation->getPlural());
+        $this->assertSame('%s has been added to your cart.', $translation->getTranslation());
+        $this->assertSame(['%s have been added to your cart.'], $translation->getPluralTranslations());
+        $this->assertCount(1, $translation->getComments());
+        $this->assertCount(0, $translation->getReferences());
+    }
+
+    public function stringDecodeProvider()
+    {
+        return [
+            ['"test"', 'test'],
+            ['"\'test\'"', "'test'"],
+            ['"Special chars: \\n \\t \\\\ "', "Special chars: \n \t \\ "],
+            ['"Newline\nSlash and n\\\\nend"', "Newline\nSlash and n\\nend"],
+            ['"Quoted \\"string\\" with %s"', 'Quoted "string" with %s'],
+            ['"\\\\x07 - aka \\\\a: \\a"', "\\x07 - aka \\a: \x07"],
+            ['"\\\\x08 - aka \\\\b: \\b"', "\\x08 - aka \\b: \x08"],
+            ['"\\\\x09 - aka \\\\t: \\t"', "\\x09 - aka \\t: \t"],
+            ['"\\\\x0a - aka \\\\n: \\n "', "\\x0a - aka \\n: \n "],
+            ['"\\\\x0b - aka \\\\v: \\v"', "\\x0b - aka \\v: \x0b"],
+            ['"\\\\x0c - aka \\\\f: \\f"', "\\x0c - aka \\f: \x0c"],
+            ['"\\\\x0d - aka \\\\r: \\r "', "\\x0d - aka \\r: \r "],
+            ['"\\\\x22 - aka \\": \\""', '\x22 - aka ": "'],
+            ['"\\\\x5c - aka \\\\: \\\\"', '\\x5c - aka \\: \\'],
+        ];
+    }
+
+    /**
+     * @dataProvider stringDecodeProvider
+     * @param mixed $source
+     * @param mixed $decoded
+     */
+    public function testStringDecode($source, $decoded)
+    {
+        $po = <<<EOT
+msgid "source"
+msgstr {$source}
+EOT;
+        $translations = $this->createPoLoader()->loadString($po);
+        $this->assertSame($decoded, $translations->find(null, 'source')->getTranslation());
+    }
+
+    public function testMultilineDisabledTranslations()
+    {
+        $po = <<<'EOT'
+#~ msgid "Last agent hours-description"
+#~ msgstr ""
+#~ "How many hours in the past can system look at finding the last agent? "
+#~ "This parameter is only used if 'Call Last Agent' is set to 'YES'."
+EOT;
+        $loader = $this->createPoLoader();
+        $translations = $loader->loadString($po);
+        $translation = $translations->find(null, 'Last agent hours-description');
+
+        $this->assertTrue($translation->isDisabled());
+        $this->assertEquals(
+            "How many hours in the past can system look at finding the last agent? This parameter is only used if 'Call Last Agent' is set to 'YES'.",
+            $translation->getTranslation()
+        );
+    }
+}
diff --git a/tests/PoLoaderTest.php b/tests/PoLoaderTest.php
index cfe4729f..3708690e 100644
--- a/tests/PoLoaderTest.php
+++ b/tests/PoLoaderTest.php
@@ -3,254 +3,14 @@
 
 namespace Gettext\Tests;
 
+use Gettext\Loader\Loader;
 use Gettext\Loader\PoLoader;
-use Gettext\Translation;
-use PHPUnit\Framework\TestCase;
 
-class PoLoaderTest extends TestCase
+class PoLoaderTest extends BasePoLoaderTestCase
 {
-    public function testPoLoader()
+    protected function createPoLoader(): Loader
     {
-        $loader = new PoLoader();
-        $translations = $loader->loadFile(__DIR__.'/assets/translations.po');
-
-        $description = $translations->getDescription();
-        $this->assertSame(
-            <<<'EOT'
-SOME DESCRIPTIVE TITLE
-Copyright (C) YEAR Free Software Foundation, Inc.
-This file is distributed under the same license as the PACKAGE package.
-FIRST AUTHOR <EMAIL@ADDRESS>, YEAR.
-EOT
-        ,
-            $description
-        );
-
-        $this->assertSame(['fuzzy'], $translations->getFlags()->toArray());
-
-        $this->assertCount(14, $translations);
-
-        $array = $translations->getTranslations();
-
-        $this->translation1(array_shift($array));
-        $this->translation2(array_shift($array));
-        $this->translation3(array_shift($array));
-        $this->translation4(array_shift($array));
-        $this->translation5(array_shift($array));
-        $this->translation6(array_shift($array));
-        $this->translation7(array_shift($array));
-        $this->translation8(array_shift($array));
-        $this->translation9(array_shift($array));
-        $this->translation10(array_shift($array));
-        $this->translation11(array_shift($array));
-        $this->translation12(array_shift($array));
-        $this->translation13(array_shift($array));
-        $this->translation14(array_shift($array));
-
-        $headers = $translations->getHeaders()->toArray();
-
-        $this->assertCount(12, $headers);
-
-        $this->assertSame('text/plain; charset=UTF-8', $headers['Content-Type']);
-        $this->assertSame('8bit', $headers['Content-Transfer-Encoding']);
-        $this->assertSame('', $headers['POT-Creation-Date']);
-        $this->assertSame('', $headers['PO-Revision-Date']);
-        $this->assertSame('', $headers['Last-Translator']);
-        $this->assertSame('', $headers['Language-Team']);
-        $this->assertSame('1.0', $headers['MIME-Version']);
-        $this->assertSame('bs', $headers['Language']);
-        $this->assertSame(
-            'nplurals=3; plural=(n%10==1 && n%100!=11 ? 0 : n%10>=2 && n%10<=4 && (n%100<10 || n%100>=20) ? 1 : 2);',
-            $headers['Plural-Forms']
-        );
-        $this->assertSame('Poedit 1.6.5', $headers['X-Generator']);
-        $this->assertSame('gettext generator test', $headers['Project-Id-Version']);
-        $this->assertSame('testingdomain', $headers['X-Domain']);
-
-        $this->assertSame('testingdomain', $translations->getDomain());
-        $this->assertSame('bs', $translations->getLanguage());
-    }
-
-    private function translation1(Translation $translation)
-    {
-        $this->assertSame(
-            'Ensure this value has at least %(limit_value)d character (it has %sd).',
-            $translation->getOriginal()
-        );
-        $this->assertSame(
-            'Ensure this value has at least %(limit_value)d characters (it has %sd).',
-            $translation->getPlural()
-        );
-        $this->assertSame('', $translation->getTranslation());
-        $this->assertSame(['', ''], $translation->getPluralTranslations());
-    }
-
-    private function translation2(Translation $translation)
-    {
-        $this->assertSame(
-            'Ensure this value has at most %(limit_value)d character (it has %sd).',
-            $translation->getOriginal()
-        );
-        $this->assertSame(
-            'Ensure this value has at most %(limit_value)d characters (it has %sd).',
-            $translation->getPlural()
-        );
-        $this->assertSame('', $translation->getTranslation());
-        $this->assertSame(['', ''], $translation->getPluralTranslations());
-    }
-
-    private function translation3(Translation $translation)
-    {
-        $this->assertSame('%ss must be unique for %ss %ss.', $translation->getOriginal());
-        $this->assertNull($translation->getPlural());
-        $this->assertSame('%ss mora da bude jedinstven za %ss %ss.', $translation->getTranslation());
-        $this->assertCount(0, $translation->getPluralTranslations());
-    }
-
-    private function translation4(Translation $translation)
-    {
-        $this->assertSame('and', $translation->getOriginal());
-        $this->assertNull($translation->getPlural());
-        $this->assertSame('i', $translation->getTranslation());
-        $this->assertCount(0, $translation->getPluralTranslations());
-        $this->assertSame(['c-format'], $translation->getFlags()->toArray());
-    }
-
-    private function translation5(Translation $translation)
-    {
-        $this->assertSame('Value %sr is not a valid choice.', $translation->getOriginal());
-        $this->assertNull($translation->getPlural());
-        $this->assertSame('', $translation->getTranslation());
-        $this->assertCount(0, $translation->getPluralTranslations());
-        $this->assertSame(['This is a extracted comment'], $translation->getExtractedComments()->toArray());
-    }
-
-    private function translation6(Translation $translation)
-    {
-        $this->assertSame('This field cannot be null.', $translation->getOriginal());
-        $this->assertNull($translation->getPlural());
-        $this->assertSame('Ovo polje ne može ostati prazno.', $translation->getTranslation());
-        $this->assertCount(0, $translation->getPluralTranslations());
-        $this->assertCount(1, $translation->getReferences());
-        $this->assertSame(['C:/Users/Me/Documents/foo2.php' => [1]], $translation->getReferences()->toArray());
-    }
-
-    private function translation7(Translation $translation)
-    {
-        $this->assertSame('This field cannot be blank.', $translation->getOriginal());
-        $this->assertNull($translation->getPlural());
-        $this->assertSame('Ovo polje ne može biti prazno.', $translation->getTranslation());
-        $this->assertCount(0, $translation->getPluralTranslations());
-        $this->assertCount(1, $translation->getReferences());
-        $this->assertSame(['C:/Users/Me/Documents/foo1.php' => []], $translation->getReferences()->toArray());
-    }
-
-    private function translation8(Translation $translation)
-    {
-        $this->assertSame('Field of type: %ss', $translation->getOriginal());
-        $this->assertNull($translation->getPlural());
-        $this->assertSame('Polje tipa: %ss', $translation->getTranslation());
-        $this->assertCount(0, $translation->getPluralTranslations());
-        $this->assertCount(2, $translation->getReferences());
-        $this->assertSame(
-            [
-                'attributes/address/composer.php' => [8],
-                'attributes/address/form.php' => [7],
-            ],
-            $translation->getReferences()->toArray()
-        );
-    }
-
-    private function translation9(Translation $translation)
-    {
-        $this->assertSame('Integer', $translation->getOriginal());
-        $this->assertNull($translation->getPlural());
-        $this->assertSame('Cijeo broj', $translation->getTranslation());
-        $this->assertCount(0, $translation->getPluralTranslations());
-        $this->assertCount(0, $translation->getReferences());
-        $this->assertCount(1, $translation->getComments());
-        $this->assertSame(['a simple line comment is above'], $translation->getComments()->toArray());
-    }
-
-    private function translation10(Translation $translation)
-    {
-        $this->assertSame('{test1}', $translation->getOriginal());
-        $this->assertNull($translation->getPlural());
-        $this->assertSame("test1\n<div>\n test2\n</div>\ntest3", $translation->getTranslation());
-        $this->assertCount(0, $translation->getPluralTranslations());
-        $this->assertCount(0, $translation->getComments());
-        $this->assertCount(3, $translation->getReferences());
-        $this->assertSame(
-            [
-                '/var/www/test/test.php' => [96, 97],
-                '/var/www/test/test2.php' => [98],
-            ],
-            $translation->getReferences()->toArray()
-        );
-    }
-
-    private function translation11(Translation $translation)
-    {
-        $this->assertSame('{test2}', $translation->getOriginal());
-        $this->assertNull($translation->getPlural());
-        $this->assertSame("test1\n<div>\n test2\n</div>\ntest3", $translation->getTranslation());
-        $this->assertCount(0, $translation->getPluralTranslations());
-        $this->assertCount(0, $translation->getComments());
-        $this->assertCount(1, $translation->getReferences());
-        $this->assertSame(
-            ['/var/www/test/test.php' => [96]],
-            $translation->getReferences()->toArray()
-        );
-    }
-
-    private function translation12(Translation $translation)
-    {
-        $this->assertSame('Multibyte test', $translation->getOriginal());
-        $this->assertNull($translation->getPlural());
-        $this->assertSame('日本人は日本で話される言語です！', $translation->getTranslation());
-        $this->assertCount(0, $translation->getPluralTranslations());
-        $this->assertCount(0, $translation->getComments());
-        $this->assertCount(0, $translation->getReferences());
-    }
-
-    private function translation13(Translation $translation)
-    {
-        $this->assertSame('Tabulation test', $translation->getOriginal());
-        $this->assertNull($translation->getPlural());
-        $this->assertSame("FIELD\tFIELD", $translation->getTranslation());
-        $this->assertCount(0, $translation->getPluralTranslations());
-        $this->assertCount(0, $translation->getComments());
-        $this->assertCount(0, $translation->getReferences());
-    }
-
-    private function translation14(Translation $translation)
-    {
-        $this->assertSame('%s has been added to your cart.', $translation->getOriginal());
-        $this->assertSame('%s have been added to your cart.', $translation->getPlural());
-        $this->assertSame('%s has been added to your cart.', $translation->getTranslation());
-        $this->assertSame(['%s have been added to your cart.'], $translation->getPluralTranslations());
-        $this->assertCount(1, $translation->getComments());
-        $this->assertCount(0, $translation->getReferences());
-    }
-
-    public function stringDecodeProvider()
-    {
-        return [
-            ['"test"', 'test'],
-            ['"\'test\'"', "'test'"],
-            ['"Special chars: \\n \\t \\\\ "', "Special chars: \n \t \\ "],
-            ['"Newline\nSlash and n\\\\nend"', "Newline\nSlash and n\\nend"],
-            ['"Quoted \\"string\\" with %s"', 'Quoted "string" with %s'],
-            ['"\\\\x07 - aka \\\\a: \\a"', "\\x07 - aka \\a: \x07"],
-            ['"\\\\x08 - aka \\\\b: \\b"', "\\x08 - aka \\b: \x08"],
-            ['"\\\\x09 - aka \\\\t: \\t"', "\\x09 - aka \\t: \t"],
-            ['"\\\\x0a - aka \\\\n: \\n"', "\\x0a - aka \\n: \n"],
-            ['"\\\\x0b - aka \\\\v: \\v"', "\\x0b - aka \\v: \x0b"],
-            ['"\\\\x0c - aka \\\\f: \\f"', "\\x0c - aka \\f: \x0c"],
-            ['"\\\\x0d - aka \\\\r: \\r"', "\\x0d - aka \\r: \r"],
-            ['"\\\\x22 - aka \\": \\""', '\x22 - aka ": "'],
-            ['"\\\\x5c - aka \\\\: \\\\"', '\\x5c - aka \\: \\'],
-        ];
+        return new PoLoader();
     }
 
     /**
@@ -262,23 +22,4 @@ public function testStringDecode($source, $decoded)
     {
         $this->assertSame($decoded, PoLoader::decode($source));
     }
-
-    public function testMultilineDisabledTranslations()
-    {
-        $po = <<<'EOT'
-#~ msgid "Last agent hours-description"
-#~ msgstr ""
-#~ "How many hours in the past can system look at finding the last agent? "
-#~ "This parameter is only used if 'Call Last Agent' is set to 'YES'."
-EOT;
-        $loader = new PoLoader();
-        $translations = $loader->loadString($po);
-        $translation = $translations->find(null, 'Last agent hours-description');
-
-        $this->assertTrue($translation->isDisabled());
-        $this->assertEquals(
-            "How many hours in the past can system look at finding the last agent? This parameter is only used if 'Call Last Agent' is set to 'YES'.",
-            $translation->getTranslation()
-        );
-    }
 }
diff --git a/tests/StrictPoLoaderTest.php b/tests/StrictPoLoaderTest.php
new file mode 100644
index 00000000..379e8b0c
--- /dev/null
+++ b/tests/StrictPoLoaderTest.php
@@ -0,0 +1,305 @@
+<?php
+declare(strict_types = 1);
+
+namespace Gettext\Tests;
+
+use Gettext\Loader\Loader;
+use Gettext\Loader\StrictPoLoader;
+
+class StrictPoLoaderTest extends BasePoLoaderTestCase
+{
+    /**
+     * @return StrictPoLoader
+     */
+    protected function createPoLoader(): Loader
+    {
+        return new StrictPoLoader();
+    }
+
+    public function stringDecodeProvider(): array
+    {
+        return array_merge(parent::stringDecodeProvider(), [
+            // Octal
+            ['"Up to 3 digits, 1 will be skipped \\0\\00\\0001"', "Up to 3 digits, 1 will be skipped \0\0\0001"],
+            ['"\\101\\102"', 'AB'],
+            // Hexadecimal
+            ['"Works with a single character \\x41\\xA\\xD\\x5A\\x5a"', "Works with a single character A\n\rZZ"],
+            ['"Last hex pair: tab = \\x12345678AAAAaaaa09"', "Last hex pair: tab = \t"],
+            // Unicode
+            ['"UTF-8, up to 4 digits \u00c0A\u00C1 \u0C0\u41\uC1"', 'UTF-8, up to 4 digits ÀAÁ ÀAÁ'],
+            ['"UTF-32, up to 8 digits \U000000c0A\U00C1 \U0C0\U41\UC1"', 'UTF-32, up to 8 digits ÀAÁ ÀAÁ'],
+        ]);
+    }
+
+    public function testCollapsedSyntax(): void
+    {
+        $po = "#   comment\nmsgctxt\"ctx\"msgid\"original\"msgstr\"trans\"\"lation\"";
+        $translations = $this->createPoLoader()->loadString($po);
+        $this->assertEquals($translations->find('ctx', 'original')->getTranslation(), 'translation');
+        $this->assertEquals($translations->find('ctx', 'original')->getComments()->toArray()[0], '  comment');
+    }
+
+    public function testPreviousTranslation(): void
+    {
+        $po = '#| msgctxt "previous ctx"
+        #| msgid "previous original"
+        #| msgid_plural "previous plural"
+        msgctxt "ctx"
+        msgid "original"
+        msgid_plural "plural"
+        msgstr[0] "translation"';
+        $translations = $this->createPoLoader()->loadString($po);
+
+        $translation = $translations->find('ctx', 'original');
+        $this->assertNotNull($translation);
+        $this->assertEquals($translation->getContext(), 'ctx');
+        $this->assertEquals($translation->getOriginal(), 'original');
+        $this->assertEquals($translation->getPlural(), 'plural');
+        $this->assertEquals($translation->getTranslation(), 'translation');
+
+        $this->assertEquals($translation->getPreviousContext(), 'previous ctx');
+        $this->assertEquals($translation->getPreviousOriginal(), 'previous original');
+        $this->assertEquals($translation->getPreviousPlural(), 'previous plural');
+    }
+
+    public function testDisabledWithPreviousTranslation(): void
+    {
+        $po = '#~ #| msgctxt "previous ctx"
+        #~ #| msgid "previous original"
+        #~ #| msgid_plural "previous plural"
+        #~ msgctxt "ctx"
+        #~ msgid "original"
+        #~ msgid_plural "plural"
+        #~ msgstr[0] "translation"';
+        $translations = $this->createPoLoader()->loadString($po);
+
+        $translation = $translations->find('ctx', 'original');
+        $this->assertNotNull($translation);
+        $this->assertTrue($translation->isDisabled());
+        $this->assertEquals($translation->getContext(), 'ctx');
+        $this->assertEquals($translation->getOriginal(), 'original');
+        $this->assertEquals($translation->getPlural(), 'plural');
+        $this->assertEquals($translation->getTranslation(), 'translation');
+
+        $this->assertEquals($translation->getPreviousContext(), 'previous ctx');
+        $this->assertEquals($translation->getPreviousOriginal(), 'previous original');
+        $this->assertEquals($translation->getPreviousPlural(), 'previous plural');
+    }
+
+    public function badFormattedPoProvider(): array
+    {
+        return [
+            'Duplicated entry' => [
+                '/Duplicated entry/',
+                'msgid"original"
+                msgstr"translation"
+                
+                msgid"original"
+                msgstr"translation 2"',
+            ],
+            'Out of order: msgstr before msgid' => [
+                '/Expected msgid/',
+                'msgstr "translation"
+                msgid "original"',
+            ],
+            'Out of order: msgctxt before msgid' => [
+                '/Expected msgid/',
+                'msgctxt "ctx"
+                msgstr "translation"
+                msgid "original"',
+            ],
+            'Out of order: Comment between the definitions' => [
+                '/Expected msgstr/',
+                'msgid "original"
+                # Unexpected comment
+                msgstr "translation"',
+            ],
+            'Out of order: Disabled translations (#~) cannot appear after previous translations (#|)' => [
+                '/Inconsistent use of #~/',
+                '#|msgid "previous"
+                #~msgid "disabled"
+                #~msgstr "disabled translation"
+                msgid "original"
+                msgstr "translation"',
+            ],
+            'Out of order: msgctxt of a previous translation (#|) must appear before its msgid' => [
+                '/Cannot redeclare the previous comment/',
+                '#|msgid "previous"
+                #|msgctxt "previous context"
+                #|msgid_plural "previous context"
+                msgid "original"
+                msgstr "translation"',
+            ],
+            'Indexed msgstr: msgid_plural requires an indexed msgstr' => [
+                '/Expected character "\\["/',
+                'msgid "original"
+                msgid_plural "plural"
+                msgstr "translation"',
+            ],
+            'Indexed msgstr: After the index 0, the next should be 2' => [
+                '/The msgstr has an invalid index/',
+                'msgid "original"
+                msgid_plural "plural"
+                msgstr[0] "translation"
+                msgstr[2] "translation"',
+            ],
+            'Indexed msgstr: Index has trash data (whitespace is ok)' => [
+                '/Expected character "]"/',
+                'msgid "original"
+                msgid_plural "plural"
+                msgstr[   0   ] "translation"
+                msgstr[1s] "translation"',
+            ],
+            'Incomplete translation' => [
+                '/Expected msgstr/',
+                'msgid "original"',
+            ],
+            'Incomplete disabled translation' => [
+                '/Expected msgstr/',
+                '#~ msgid "original"',
+            ],
+            'Encoding: No quotes' => [
+                '/Expected an opening quote/',
+                'msgid "original"
+                msgstr translation',
+            ],
+            'Encoding: Missing opening quote' => [
+                '/Expected an opening quote/',
+                'msgid "original"
+                msgstr translation"',
+            ],
+            'Encoding: Missing closing quote' => [
+                '/Expected a closing quot/',
+                'msgid "original"
+                msgstr "translation',
+            ],
+            'Encoding: Unescaped newline (using \\n)' => [
+                '/Newline character must be escaped/',
+                "msgid \"original\"
+                msgstr \"trans\nlation\"",
+            ],
+            'Encoding: Unescaped newline (using \\r)' => [
+                '/Newline character must be escaped/',
+                "msgid \"original\"
+                msgstr \"trans\rlation\"",
+            ],
+            'Encoding: Invalid octal digit' => [
+                '/Invalid escaped character/',
+                'msgid "original"
+                msgstr "translation\8"',
+            ],
+            'Encoding: Octal out of range' => [
+                '/Octal value out of range/',
+                'msgid "original"
+                msgstr "translation\777"',
+            ],
+            'Encoding: Invalid hexadecimal digit' => [
+                '/Expected at least 1 occurrence of hexadecimal/',
+                'msgid "original"
+                msgstr "translation\xGG"',
+            ],
+            'Encoding: Invalid unicode digit' => [
+                '/Expected at least 1 occurrence of hexadecimal/',
+                'msgid "original"
+                msgstr "translation\uZZ"',
+            ],
+            'Invalid identifier "unknown"' => [
+                '/Expected msgid/',
+                'unknown "original"
+                msgstr "translation"',
+            ],
+            // The checks below depends on the $throwOnWarning = true
+            'msgid, msgid_plural and msgstr cannot begin nor end with a newline' => [
+                '/msgstr cannot start nor end with a newline/',
+                'msgid "original"
+                msgstr "translation\n"',
+                true,
+            ],
+            'Missing header' => [
+                '/The loaded string has no header translation/',
+                'msgid "original"
+                msgstr "translation"',
+                true,
+            ],
+            'Duplicated header' => [
+                '/Header already defined/',
+                'msgid ""
+                msgstr "Header: \\n"
+                "Header: \\n"',
+                true,
+            ],
+            'Malformed header name' => [
+                '/Malformed header name/',
+                'msgid ""
+                msgstr "Header\\n"',
+                true,
+            ],
+            'Missing standard headers Language/Plural-Forms/Content-Type' => [
+                '/header not declared or empty/',
+                'msgid ""
+                msgstr "Header: Value\\n"',
+                true,
+            ],
+            'Two plural forms with just one plural translation' => [
+                '/The translation has \\d+ plural forms, while the header expects \\d+/',
+                'msgid ""
+                msgstr "Language: en_US\n"
+                "Content-Type: text/plain; charset=UTF-8\n"
+                "Plural-Forms: nplurals=2; plural=n != 1;\n"
+
+                msgid "original"
+                msgid_plural "plural"
+                msgstr[0] "translation"',
+                true,
+            ],
+            'Two plural forms with 3 plural translations' => [
+                '/The translation has \\d+ plural forms, while the header expects \\d+/',
+                'msgid ""
+                msgstr "Language: en_US\n"
+                "Content-Type: text/plain; charset=UTF-8\n"
+                "Plural-Forms: nplurals=2; plural=n != 1;\n"
+
+                msgid "original"
+                msgid_plural "plural"
+                msgstr[0] "translation"
+                msgstr[1] "translation"
+                msgstr[2] "translation"',
+                true,
+            ],
+            'Dangling comment in the end of the data' => [
+                '/Comment ignored at the end/',
+                'msgid "original"
+                msgstr "translation"
+                
+                # Dangling comment',
+                true,
+            ],
+            'Dangling comment in the end of the data using error report with line/column' => [
+                '/Comment ignored at the end.*line 4 column 34/',
+                'msgid "original"
+                msgstr "translation"
+                
+                # Dangling comment',
+                true,
+                true,
+            ],
+        ];
+    }
+
+    /**
+     * @dataProvider badFormattedPoProvider
+     */
+    public function testBadFormattedPo(
+        string $exceptionPattern,
+        string $po,
+        bool $throwOnWarning = false,
+        bool $displayErrorLine = false
+    ): void
+    {
+        $this->expectExceptionMessageMatches($exceptionPattern);
+        $loader = $this->createPoLoader();
+        $loader->throwOnWarning = $throwOnWarning;
+        $loader->displayErrorLine = $displayErrorLine;
+        $loader->loadString($po);
+    }
+}
diff --git a/tests/assets/translations.po b/tests/assets/translations.po
index b172a8ed..d37fbf0b 100644
--- a/tests/assets/translations.po
+++ b/tests/assets/translations.po
@@ -2,7 +2,6 @@
 # Copyright (C) YEAR Free Software Foundation, Inc.
 # This file is distributed under the same license as the PACKAGE package.
 # FIRST AUTHOR <EMAIL@ADDRESS>, YEAR.
-#
 #, fuzzy
 msgid ""
 msgstr ""
diff --git a/tests/snapshots/testNoStrategy.php b/tests/snapshots/testNoStrategy.php
index 0271284e..f26af6aa 100644
--- a/tests/snapshots/testNoStrategy.php
+++ b/tests/snapshots/testNoStrategy.php
@@ -21,6 +21,9 @@
             'plural' => null,
             'pluralTranslations' => [],
             'disabled' => false,
+            'previousContext' => null,
+            'previousOriginal' => null,
+            'previousPlural' => null,
             'references' => [
                 'template.php' => [
                     3,
@@ -42,6 +45,9 @@
             'plural' => null,
             'pluralTranslations' => [],
             'disabled' => true,
+            'previousContext' => null,
+            'previousOriginal' => null,
+            'previousPlural' => null,
             'references' => [
                 'template.php' => [
                     4
@@ -63,6 +69,9 @@
                 '%s comentarios'
             ],
             'disabled' => false,
+            'previousContext' => null,
+            'previousOriginal' => null,
+            'previousPlural' => null,
             'references' => [
                 'template.php' => [
                     5,
@@ -83,6 +92,9 @@
             'plural' => null,
             'pluralTranslations' => [],
             'disabled' => false,
+            'previousContext' => null,
+            'previousOriginal' => null,
+            'previousPlural' => null,
             'references' => [
                 'template.php' => [
                     10
@@ -105,6 +117,9 @@
             'plural' => null,
             'pluralTranslations' => [],
             'disabled' => false,
+            'previousContext' => null,
+            'previousOriginal' => null,
+            'previousPlural' => null,
             'references' => [
                 'template.php' => [
                     11
@@ -122,6 +137,9 @@
             'plural' => null,
             'pluralTranslations' => [],
             'disabled' => false,
+            'previousContext' => null,
+            'previousOriginal' => null,
+            'previousPlural' => null,
             'references' => [
                 'template.php' => [
                     2
diff --git a/tests/snapshots/testScanAndLoadStrategy.php b/tests/snapshots/testScanAndLoadStrategy.php
index 272bcebc..91e970ad 100644
--- a/tests/snapshots/testScanAndLoadStrategy.php
+++ b/tests/snapshots/testScanAndLoadStrategy.php
@@ -19,6 +19,9 @@
             'plural' => null,
             'pluralTranslations' => [],
             'disabled' => false,
+            'previousContext' => null,
+            'previousOriginal' => null,
+            'previousPlural' => null,
             'references' => [
                 'template.php' => [
                     3
@@ -36,6 +39,9 @@
             'plural' => null,
             'pluralTranslations' => [],
             'disabled' => true,
+            'previousContext' => null,
+            'previousOriginal' => null,
+            'previousPlural' => null,
             'references' => [
                 'template.php' => [
                     4
@@ -57,6 +63,9 @@
                 '%s comentarios'
             ],
             'disabled' => false,
+            'previousContext' => null,
+            'previousOriginal' => null,
+            'previousPlural' => null,
             'references' => [
                 'template.php' => [
                     5
@@ -76,6 +85,9 @@
             'plural' => null,
             'pluralTranslations' => [],
             'disabled' => false,
+            'previousContext' => null,
+            'previousOriginal' => null,
+            'previousPlural' => null,
             'references' => [
                 'template.php' => [
                     10
@@ -97,6 +109,9 @@
             'plural' => null,
             'pluralTranslations' => [],
             'disabled' => false,
+            'previousContext' => null,
+            'previousOriginal' => null,
+            'previousPlural' => null,
             'references' => [
                 'template.php' => [
                     11
diff --git a/tests/snapshots/testUpdateTemplatesEntries.php b/tests/snapshots/testUpdateTemplatesEntries.php
deleted file mode 100644
index b53aa030..00000000
--- a/tests/snapshots/testUpdateTemplatesEntries.php
+++ /dev/null
@@ -1,109 +0,0 @@
-<?php
-return [
-    'headers' => [
-        'Language' => 'gl_ES',
-        'Language-Team' => 'My Team',
-        'Last-Translator' => 'Oscar',
-        'POT-Creation-Date' => '2019-10-10 10:10:10',
-        'X-Domain' => 'my-domain',
-        'X-Foo' => 'bar',
-        'X-Generator' => 'PHP Gettext scanner',
-    ],
-    'translations' => [
-        [
-            'id' => 'title',
-            'context' => null,
-            'original' => 'title',
-            'translation' => 'Título',
-            'plural' => null,
-            'pluralTranslations' => [],
-            'disabled' => false,
-            'references' => [
-                'template.php' => [
-                    3,
-                ],
-            ],
-            'flags' => [],
-            'comments' => [],
-            'extractedComments' => [],
-        ],
-        [
-            'id' => 'intro',
-            'context' => null,
-            'original' => 'intro',
-            'translation' => 'Intro',
-            'plural' => null,
-            'pluralTranslations' => [],
-            'disabled' => true,
-            'references' => [
-                'template.php' => [
-                    4,
-                ],
-            ],
-            'flags' => [],
-            'comments' => [
-                'Disabled comment',
-            ],
-            'extractedComments' => [],
-        ],
-        [
-            'id' => 'one comment',
-            'context' => null,
-            'original' => 'one comment',
-            'translation' => 'Un comentario',
-            'plural' => '%s comments',
-            'pluralTranslations' => [
-                '%s comentarios',
-            ],
-            'disabled' => false,
-            'references' => [
-                'template.php' => [
-                    5,
-                ],
-            ],
-            'flags' => [],
-            'comments' => [],
-            'extractedComments' => [
-                'Number of comments of the article',
-            ],
-        ],
-        [
-            'id' => 'This is a flagged element',
-            'context' => null,
-            'original' => 'This is a flagged element',
-            'translation' => null,
-            'plural' => null,
-            'pluralTranslations' => [],
-            'disabled' => false,
-            'references' => [
-                'template.php' => [
-                    10,
-                ],
-            ],
-            'flags' => [
-                'a-code',
-            ],
-            'comments' => [
-                'This is a comment',
-            ],
-            'extractedComments' => [],
-        ],
-        [
-            'id' => 'This is a new translation',
-            'context' => null,
-            'original' => 'This is a new translation',
-            'translation' => null,
-            'plural' => null,
-            'pluralTranslations' => [],
-            'disabled' => false,
-            'references' => [
-                'template.php' => [
-                    11,
-                ],
-            ],
-            'flags' => [],
-            'comments' => [],
-            'extractedComments' => [],
-        ],
-    ],
-];