diff --git a/progit/templates/pull_request.html b/progit/templates/pull_request.html
index 4445804..e04f3e4 100644
--- a/progit/templates/pull_request.html
+++ b/progit/templates/pull_request.html
@@ -116,7 +116,8 @@
     {{ diff_commits[loop.index - 1].message }}
     </p>
     {% autoescape false %}
-        {{ html_diff | format_loc(diff_commits[loop.index - 1], request) }}
+        {{ html_diff | format_loc(diff_commits[loop.index - 1], request,
+            index=loop.index) }}
     {% endautoescape %}
   {% endfor %}
 </section>