diff --git a/src/Util/Printer.php b/src/Util/Printer.php
index b36d1656c3e..9b52f322ed5 100644
--- a/src/Util/Printer.php
+++ b/src/Util/Printer.php
@@ -15,7 +15,7 @@
 class Printer
 {
     /**
-     * @var resource
+     * @var closed-resource|resource
      */
     private $stream;
 
@@ -74,6 +74,8 @@ public function __construct($out = null)
     public function write(string $buffer): void
     {
         if ($this->stream) {
+            \assert(\is_resource($this->stream));
+
             \fwrite($this->stream, $buffer);
         } else {
             if (\PHP_SAPI !== 'cli' && \PHP_SAPI !== 'phpdbg') {
@@ -87,6 +89,8 @@ public function write(string $buffer): void
     public function flush(): void
     {
         if ($this->stream && $this->isPhpStream) {
+            \assert(\is_resource($this->stream));
+
             \fclose($this->stream);
         }
     }
diff --git a/src/Util/Test.php b/src/Util/Test.php
index 19870acebc5..4bef60cedf2 100644
--- a/src/Util/Test.php
+++ b/src/Util/Test.php
@@ -162,7 +162,7 @@ public static function getMissingRequirements(string $className, string $methodN
 
             if (!\version_compare(\PHP_VERSION, $required['PHP']['version'], $operator->asString())) {
                 $missing[] = \sprintf('PHP %s %s is required.', $operator->asString(), $required['PHP']['version']);
-                $hint      = $hint ?? 'PHP';
+                $hint      = 'PHP';
             }
         } elseif (!empty($required['PHP_constraint'])) {
             $version = new \PharIo\Version\Version(self::sanitizeVersionNumber(\PHP_VERSION));
@@ -173,7 +173,7 @@ public static function getMissingRequirements(string $className, string $methodN
                     $required['PHP_constraint']['constraint']->asString()
                 );
 
-                $hint = $hint ?? 'PHP_constraint';
+                $hint = 'PHP_constraint';
             }
         }