diff --git a/Parser/MarkdownParser.php b/Parser/MarkdownParser.php
index df369b3..378786a 100644
--- a/Parser/MarkdownParser.php
+++ b/Parser/MarkdownParser.php
@@ -124,7 +124,7 @@ class MarkdownParser extends MarkdownExtra implements MarkdownParserInterface
     /**
      * Simplify detab
      */
-    public function detab($text)
+    public function detab($text): string
     {
         return str_replace("\t", str_repeat(' ', $this->tab_width), $text);
     }
diff --git a/Twig/Extension/MarkdownTwigExtension.php b/Twig/Extension/MarkdownTwigExtension.php
index e9ab8c0..9d20683 100644
--- a/Twig/Extension/MarkdownTwigExtension.php
+++ b/Twig/Extension/MarkdownTwigExtension.php
@@ -15,19 +15,19 @@ class MarkdownTwigExtension extends AbstractExtension
         $this->parserManager = $parserManager;
     }
 
-    public function getFilters()
+    public function getFilters(): array
     {
         return array(
             new TwigFilter('markdown', array($this, 'markdown'), array('is_safe' => array('html'))),
         );
     }
 
-    public function markdown($text, $parser = null)
+    public function markdown($text, $parser = null): string
     {
         return $this->parserManager->transform($text, $parser);
     }
 
-    public function getName()
+    public function getName(): string
     {
         return 'markdown';
     }