--- a/stage1_2/iec_flex.ll	Sun Jul 06 23:31:08 2014 +0100
+++ b/stage1_2/iec_flex.ll	Sun Jul 13 12:26:58 2014 +0100
@@ -1251,8 +1251,8 @@
 	/******************************************************/
 
 
-REF	{if (get_opt_ref_operator()) return REF;    else unput(0);}		/* Keyword in IEC 61131-3 v3 */
-REF_TO	{/*if (get_opt_ref_operator()) return REF_TO; else */unput(0);}		/* Keyword in IEC 61131-3 v3 */
+REF	{if (get_opt_ref_operator()) return REF;    else{REJECT;}}		/* Keyword in IEC 61131-3 v3 */
+REF_TO	{if (get_opt_ref_operator()) return REF_TO; else{REJECT;}}		/* Keyword in IEC 61131-3 v3 */
 
 EN	return EN;			/* Keyword */
 ENO	return ENO;			/* Keyword */