diff --git a/base/dict.c b/base/dict.c
index 6fa5658df..37f4b95bd 100644
--- a/base/dict.c
+++ b/base/dict.c
@@ -253,7 +253,7 @@ heim_dict_delete_key(heim_dict_t dict, heim_object_t key)
  */
 
 void
-heim_dict_iterate_f(heim_dict_t dict, heim_dict_iterator_f_t func, void *arg)
+heim_dict_iterate_f(heim_dict_t dict, void *arg, heim_dict_iterator_f_t func)
 {
     struct hashentry **h, *g;