diff --git a/include/linux/mtd/map.h b/include/linux/mtd/map.h
index 01703d425986..de89eca864ce 100644
--- a/include/linux/mtd/map.h
+++ b/include/linux/mtd/map.h
@@ -387,6 +387,8 @@ static inline map_word inline_map_read(struct map_info *map, unsigned long ofs)
 #endif
 	else if (map_bankwidth_is_large(map))
 		memcpy_fromio(r.x, map->virt+ofs, map->bankwidth);
+	else
+		BUG();
 
 	return r;
 }