diff --git a/hw/xfree86/parser/Flags.c b/hw/xfree86/parser/Flags.c
index b4e8d25..5dc079e 100644
--- a/hw/xfree86/parser/Flags.c
+++ b/hw/xfree86/parser/Flags.c
@@ -239,7 +239,8 @@ xf86optionListDup (XF86OptionPtr opt)
 	while (opt)
 	{
 		newopt = xf86addNewOption(newopt, strdup(opt->opt_name), 
-					  strdup(opt->opt_val));
+					  (opt->opt_val != NULL)?
+					   strdup(opt->opt_val):NULL);
 		newopt->opt_used = opt->opt_used;
 		if (opt->opt_comment)
 			newopt->opt_comment = strdup(opt->opt_comment);