diff --git a/src/DataCollection.php b/src/DataCollection.php
index 03b41bf0e..6fb8ed27c 100644
--- a/src/DataCollection.php
+++ b/src/DataCollection.php
@@ -101,7 +101,7 @@ public function getIterator(): ArrayIterator
         return new ArrayIterator($this->transform(TransformationType::withoutValueTransforming()));
     }
 
-    public function count()
+    public function count(): int
     {
         return count($this->items);
     }