diff --git a/drivers/video/cirrusfb.c b/drivers/video/cirrusfb.c
index f99cb77..f7e2d5a 100644
--- a/drivers/video/cirrusfb.c
+++ b/drivers/video/cirrusfb.c
@@ -2509,8 +2509,7 @@
 	cinfo = info->par;
 	cinfo->btype = btype;
 
-	assert(z > 0);
-	assert(z2 >= 0);
+	assert(z);
 	assert(btype != BT_NONE);
 
 	cinfo->zdev = z;