diff --git a/src/frontend/numparam/xpressn.c b/src/frontend/numparam/xpressn.c
index 79226be99..a27bed2ec 100644
--- a/src/frontend/numparam/xpressn.c
+++ b/src/frontend/numparam/xpressn.c
@@ -524,7 +524,7 @@ nupa_define(dico_t *dico,
 
         } else {
             /* error message for redefinition of symbols */
-            message(dico, "%s is already used,\n cannot be redefined\n", t);
+            fprintf(stderr, "Warning: %s is already used,\n cannot be redefined\n", t);
         }
     }