diff --git a/mk/config.mk.in b/mk/config.mk.in
index 2b670cc95ac824c8ba8ed723fa26f15f896f8a48..901b2d1dc8c5b74ce3f8915f61ff63246d182948 100644
--- a/mk/config.mk.in
+++ b/mk/config.mk.in
@@ -709,7 +709,7 @@ WAY_t_HC_OPTS= -ticky
 
 # Way `u':
 WAY_u_NAME=unregisterized (using portable C only)
-WAY_u_HC_OPTS=
+WAY_u_HC_OPTS=-unreg
 
 # Way `mp': 
 WAY_mp_NAME=parallel