diff --git a/server-ca/payment.py b/server-ca/payment.py
index 52ffa28a6..f500f09f7 100755
--- a/server-ca/payment.py
+++ b/server-ca/payment.py
@@ -39,7 +39,7 @@ class payment(object):
         names = r.lrange("%s:names" % session, 0, -1)
         names_list = '<ul style="font-family:monospace">' + "\n".join("<li>%s</li>" % n for n in names) + '</ul>'
         with open("thanks.html","r") as f:
-            return f.read() % (session, names)
+            return f.read() % (session, names_list)
 
 if __name__ == "__main__":
     app = web.application(urls, globals())