diff --git a/relaxng.c b/relaxng.c
index 075fc4a..6dbc499 100644
--- a/relaxng.c
+++ b/relaxng.c
@@ -5369,7 +5369,8 @@
     } else {
         xmlRngPErr(ctxt, node, XML_RNGP_CHOICE_CONTENT,
                    "expecting name, anyName, nsName or choice : got %s\n",
-                   (node == NULL ? "nothing" : node->name), NULL);
+                   (node == NULL ? (const xmlChar *) "nothing" : node->name),
+		   NULL);
         return (NULL);
     }
     if (ret != def) {
@@ -9459,7 +9460,8 @@
             ctxt->states = NULL;
             if (found == 0) {
                 if (cur == NULL) {
-                    VALID_ERR2(XML_RELAXNG_ERR_INTEREXTRA, "noname");
+		    VALID_ERR2(XML_RELAXNG_ERR_INTEREXTRA,
+			       (const xmlChar *) "noname");
                 } else {
                     VALID_ERR2(XML_RELAXNG_ERR_INTEREXTRA, cur->name);
                 }