diff --git a/src/message.c b/src/message.c
index a4d2cc8..06f8cb9 100644
--- a/src/message.c
+++ b/src/message.c
@@ -3746,7 +3746,7 @@
 	    }
 
 	    /* advance to the next character */
-	    mb_ptr_adv(r);
+	    MB_PTR_ADV(r);
 	}
 
 	if (copy)