diff --git a/features/save-to-source.feature b/features/save-to-source.feature
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+Feature: Save to source
+  Scenario: Save to source
+    Given I have a responsive_image configuration with:
+      """
+        save_to_source: true
+        sizes:
+          - width: 100
+        extra_images:
+          - assets/everybody-loves-jalapeño-pineapple-cornbread.png
+          - assets/*.jpeg
+      """
+    And I have a file "index.html" with "Hello, world!"
+    When I run Jekyll
+    And the file "assets/resized/everybody-loves-jalapeño-pineapple-cornbread-100x50.png" should exist
+    And the file "assets/resized/progressive-100x50.jpeg" should exist
+    And the file "_site/assets/resized/everybody-loves-jalapeño-pineapple-cornbread-100x50.png" should exist
+    And the file "_site/assets/resized/progressive-100x50.jpeg" should exist
+
+  Scenario: Do not save to source
+    Given I have a responsive_image configuration with:
+      """
+        save_to_source: false
+        sizes:
+          - width: 100
+        extra_images:
+          - assets/everybody-loves-jalapeño-pineapple-cornbread.png
+          - assets/*.jpeg
+      """
+    And I have a file "index.html" with "Hello, world!"
+    When I run Jekyll
+    And the file "assets/resized/everybody-loves-jalapeño-pineapple-cornbread-100x50.png" should not exist
+    And the file "assets/resized/progressive-100x50.jpeg" should not exist
+    And the file "_site/assets/resized/everybody-loves-jalapeño-pineapple-cornbread-100x50.png" should exist
+    And the file "_site/assets/resized/progressive-100x50.jpeg" should exist
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