diff --git a/hgsane/sane_hg_mdw.cpp b/hgsane/sane_hg_mdw.cpp
index b2f48f9..043d89d 100644
--- a/hgsane/sane_hg_mdw.cpp
+++ b/hgsane/sane_hg_mdw.cpp
@@ -259,7 +259,7 @@ namespace local_utility
 	// fixed id map
 	static void init_fixed_id(const char* name, int id, std::map<sane_option_id, int>& mapid)
 	{
-	#define TRY_MATCH(n, m)								\
+	#define TRY_MATCH(n)								\
 		if(strcmp(SANE_STD_OPT_NAME_##n, name) == 0)	\
 		{												\
 			mapid[SANE_OPT_ID_##n] = id;				\