diff --git a/src/dstr.c b/src/dstr.c
index 9c64fa2..9c12e8a 100644
--- a/src/dstr.c
+++ b/src/dstr.c
@@ -65,9 +65,11 @@ int uc_dstr_ensure(struct DStr *str, size_t total)
 void uc_dstr_reset(struct DStr *str)
 {
     str->len = 0;
+#ifdef DEBUG
     if (str->str) {
-        str->str[0] = 0;
+        memset(str->str, 0xcc, str->allocated);
     }
+#endif
 }
 
 void uc_dstr_terminate(struct DStr *str)