diff --git a/libvo/mga_common.c b/libvo/mga_common.c
index 2477e4bf8c..cf2d8c19b9 100644
--- a/libvo/mga_common.c
+++ b/libvo/mga_common.c
@@ -397,7 +397,7 @@ static int mga_uninit(){
 
 static uint32_t preinit(const char *vo_subdevice)
 {
-  char *devname=vo_subdevice?vo_subdevice:"/dev/mga_vid";
+  const char *devname=vo_subdevice?vo_subdevice:"/dev/mga_vid";
 
 	f = open(devname,O_RDWR);
 	if(f == -1)