diff -ur mscgen-0.20.old/src/language.y mscgen-0.20/src/language.y
--- mscgen-0.20.old/src/language.y	2016-07-25 10:59:11.000000000 +0000
+++ mscgen-0.20/src/language.y	2016-07-25 11:36:33.608945391 +0000
@@ -39,16 +39,13 @@
 /* Use verbose error reporting such that the expected token names are dumped */
 #define YYERROR_VERBOSE
 
-/* Name of parameter that is passed to yyparse() */
-#define YYPARSE_PARAM yyparse_result
-
 #define YYMALLOC malloc_s
 
 /* yyerror
  *  Error handling function.  The TOK_XXX names are substituted for more
  *  understandable values that make more sense to the user.
  */
-void yyerror(const char *str)
+void yyerror( void *yyparse_result, const char *str)
 {
     static const char *tokNames[] = { "TOK_OCBRACKET",          "TOK_CCBRACKET",
                                       "TOK_OSBRACKET",          "TOK_CSBRACKET",
@@ -224,6 +221,8 @@
 
 %}
 
+%parse-param { void *yyparse_result}
+
 %token TOK_STRING TOK_QSTRING TOK_EQUAL TOK_COMMA TOK_SEMICOLON TOK_OCBRACKET TOK_CCBRACKET
        TOK_OSBRACKET TOK_CSBRACKET TOK_MSC
        TOK_ATTR_LABEL TOK_ATTR_URL TOK_ATTR_ID TOK_ATTR_IDURL