diff --git a/features/image-generation.feature b/features/image-generation.feature
index b7a8e50..98ad005 100644
--- a/features/image-generation.feature
+++ b/features/image-generation.feature
@@ -28,6 +28,7 @@ Feature: Responsive image generation
       """
         {% responsive_image path: assets/test.png %}
         {% responsive_image path: assets/subdir/test.png %}
+        {% responsive_image path: assets/test.png cache: true %}
       """
 
     When I run Jekyll