diff --git a/src/flextype/Endpoints/images.php b/src/flextype/Endpoints/images.php
index c9d32958..a0d7e771 100644
--- a/src/flextype/Endpoints/images.php
+++ b/src/flextype/Endpoints/images.php
@@ -19,7 +19,7 @@ use function flextype;
 /**
  * Validate images token
  */
-function validate_images_token($token): bool
+function validate_images_token(string $token): bool
 {
     return filesystem()->file(PATH['project'] . '/tokens/images/' . $token . '/token.yaml')->exists();
 }