diff --git a/vex.h b/vex.h
index 82417e4..0553c53 100644
--- a/vex.h
+++ b/vex.h
@@ -25,6 +25,21 @@
 extern "C" {
 #endif
 
+#ifdef YYPARSE_PARAM
+#if defined __STDC__ || defined __cplusplus
+int yyparse (void *YYPARSE_PARAM);
+#else
+int yyparse ();
+#endif
+#else /* ! YYPARSE_PARAM */
+#if defined __STDC__ || defined __cplusplus
+int yyparse (void);
+#else
+int yyparse ();
+#endif
+#endif /* ! YYPARSE_PARAM */
+
+  
 /* structure declarations */
 
 struct llist {