diff --git a/kamailio/default.cfg b/kamailio/default.cfg
index 76427a5..7a2edc1 100644
--- a/kamailio/default.cfg
+++ b/kamailio/default.cfg
@@ -423,7 +423,7 @@ route[INTERNAL_TO_EXTERNAL_RELAY]
         }
     #!endif
 
-    remove_hf_re("X-.*");
+    remove_hf_re("^X-.*");
 
     t_on_reply("EXTERNAL_REPLY");