diff --git a/src/Twig/FormatCronExtension.php b/src/Twig/FormatCronExtension.php
index fa5da2f..1f0fa66 100644
--- a/src/Twig/FormatCronExtension.php
+++ b/src/Twig/FormatCronExtension.php
@@ -57,7 +57,7 @@ class FormatCronExtension extends AbstractExtension implements GlobalsInterface
         ];
     }
 
-    public function getGlobals()
+    public function getGlobals(): array
     {
         return [];
     }