diff --git a/composer.json b/composer.json
index 3a7038c..b427824 100644
--- a/composer.json
+++ b/composer.json
@@ -21,9 +21,9 @@
   "require": {
     "php": ">=7.3.0",
     "ext-json": "*",
-    "picocms/pico": "^2.1",
-    "picocms/pico-theme": "^2.1",
-    "picocms/pico-deprecated": "^2.1",
+    "picocms/pico": "dev-pico-3.0#a5fefa4",
+    "picocms/pico-theme": "dev-pico-3.0#f322a0b",
+    "picocms/pico-deprecated": "dev-pico-3.0#ccf1194",
     "picocms/composer-installer": "^1.0",
     "xemlock/htmlpurifier-html5": "~0.1.11",
     "symfony/yaml" : "^2.8|^3.4|^4.4|^5.1"
@@ -31,8 +31,7 @@
   "require-dev": {
     "phpunit/phpunit": "^8",
     "phrozenbyte/phpunit-throwable-asserts": "^1.1",
-    "phrozenbyte/phpunit-array-asserts": "^v1.1",
-    "incompass/coverage": "^1.0"
+    "phrozenbyte/phpunit-array-asserts": "^v1.1"
   },
   "extra": {
     "pico-theme-dir": "appdata/themes/",
diff --git a/lib/Model/Plugin.php b/lib/Model/Plugin.php
index aa39896..a5b2afb 100644
--- a/lib/Model/Plugin.php
+++ b/lib/Model/Plugin.php
@@ -46,6 +46,7 @@ class Plugin implements \JsonSerializable
 		Pico::API_VERSION_1,
 		Pico::API_VERSION_2,
 		Pico::API_VERSION_3,
+		Pico::API_VERSION_4,
 	];
 
 	/** @var MiscService */
diff --git a/lib/Pico.php b/lib/Pico.php
index a426554..8a66e03 100644
--- a/lib/Pico.php
+++ b/lib/Pico.php
@@ -71,6 +71,13 @@ class Pico extends \Pico
 	 */
 	public const API_VERSION_3 = 3;
 
+	/**
+	 * API version 4, used by Pico 3.0
+	 *
+	 * @var int
+	 */
+	public const API_VERSION_4 = 4;
+
 	/** @var PicoService */
 	private $picoService;
 
@@ -104,7 +111,7 @@ class Pico extends \Pico
 	 * @throws NotFoundException
 	 * @throws NotPermittedException
 	 */
-	public function run()
+	public function run() : string
 	{
 		return parent::run();
 	}
@@ -141,7 +148,7 @@ class Pico extends \Pico
 	 *
 	 * @return void
 	 */
-	protected function evaluateRequestUrl()
+	protected function evaluateRequestUrl() : void
 	{
 		// do nothing
 	}
@@ -157,7 +164,7 @@ class Pico extends \Pico
 	 * @throws NotFoundException
 	 * @throws NotPermittedException
 	 */
-	public function loadFileContent($absolutePath)
+	public function loadFileContent($absolutePath) : string
 	{
 		/** @var FolderInterface $folder */
 		/** @var string $basePath */
@@ -177,7 +184,7 @@ class Pico extends \Pico
 	 * @return array
 	 * @throws ParseException
 	 */
-	public function parseFileMeta($rawContent, array $headers)
+	public function parseFileMeta($rawContent, array $headers) : array
 	{
 		$meta = parent::parseFileMeta($rawContent, $headers);
 		return $this->purifyFileMeta($meta);
@@ -212,7 +219,7 @@ class Pico extends \Pico
 	 *
 	 * @return string
 	 */
-	public function parseFileContent($markdown, $singleLine = false)
+	public function parseFileContent($markdown, $singleLine = false) : string
 	{
 		$content = parent::parseFileContent($markdown, $singleLine);
 		return $this->purifyFileContent($content);
@@ -275,7 +282,7 @@ class Pico extends \Pico
 	 * @throws WebsiteInvalidFilesystemException
 	 * @throws InvalidPathException
 	 */
-	public function getFiles($absolutePath, $fileExtension = '', $order = \Pico::SORT_ASC)
+	public function getFiles($absolutePath, $fileExtension = '', $order = \Pico::SORT_ASC) : array
 	{
 		/** @var FolderInterface $folder */
 		/** @var string $basePath */
@@ -327,7 +334,7 @@ class Pico extends \Pico
 	 * @throws WebsiteInvalidFilesystemException
 	 * @throws InvalidPathException
 	 */
-	public function getFilesGlob($absolutePathPattern, $order = \Pico::SORT_ASC)
+	public function getFilesGlob($absolutePathPattern, $order = \Pico::SORT_ASC) : array
 	{
 		/** @var FolderInterface $folder */
 		/** @var string $basePath */