diff --git a/src/util/util.c b/src/util/util.c
index 10d5d53f7..e82be368d 100644
--- a/src/util/util.c
+++ b/src/util/util.c
@@ -270,7 +270,7 @@ TALER_url_join (const char *base_url,
   GNUNET_assert (NULL != base_url);
   GNUNET_assert (NULL != path);
 
-  if (strlen (base_url) == 0)
+  if (0 == strlen (base_url))
   {
     /* base URL can't be empty */
     GNUNET_break (0);