diff --git a/doc/source/images/generate-diffs b/doc/source/images/generate-diffs.sh
similarity index 100%
rename from doc/source/images/generate-diffs
rename to doc/source/images/generate-diffs.sh
diff --git a/doc/source/tutorial/README b/doc/source/tutorial/README
index b8473b1ec737798a51b370d3aa40c7e74ed8656b..b7174b90ca4f4b03d20930042b58a4e9182daeb3 100644
--- a/doc/source/tutorial/README
+++ b/doc/source/tutorial/README
@@ -7,5 +7,5 @@ and running ``make doc/source/images/SCRIPT.py`` in doc.  Now examine the newly
 created doc/source/images/SCRIPT.py.  If you do not like the result or the
 patch did not apply, edit doc/source/images/SCRIPT.py until you like it.  You
 can run `make html` during your edits to check things.  Finally, even if you
-did not edit the script, execute generate-diffs in doc/source/images.  If
+did not edit the script, execute generate-diffs.sh in doc/source/images.  If
 the patches applied cleanly the diff files will usually stay unchanged.