diff --git a/owlps-udp-to-http/owlps-udp-to-http.c b/owlps-udp-to-http/owlps-udp-to-http.c
index 5fb9cd8..c83125d 100644
--- a/owlps-udp-to-http/owlps-udp-to-http.c
+++ b/owlps-udp-to-http/owlps-udp-to-http.c
@@ -496,11 +496,14 @@ void realloc_answer(size_t new_size)
  */
 void free_results_list()
 {
-  results_list *ptr = results ;
-  while (ptr != NULL)
+  while (results != NULL)
     {
-      owl_free_result(ptr->result) ;
-      ptr = ptr->next ;
+      owl_free_result(results->result) ;
+      results = results->next ;
+#ifndef NDEBUG
+      --nb_results ;
+#endif // NDEBUG
     }
+  assert(nb_results == 0) ;
   nb_results = 0 ;
 }