diff --git a/docs/intro/reusable-apps.txt b/docs/intro/reusable-apps.txt
index f40daf4dfbd..0ca63830ea0 100644
--- a/docs/intro/reusable-apps.txt
+++ b/docs/intro/reusable-apps.txt
@@ -76,7 +76,7 @@ After the previous tutorials, our project should look like this:
             static/
                 polls/
                     images/
-                        background.gif
+                        background.png
                     style.css
             templates/
                 polls/