diff --git a/drivers/gpu/drm/radeon/radeon_vm.c b/drivers/gpu/drm/radeon/radeon_vm.c
index 2aae6ce49d3286888ea22347b60d71cc5220eef4..d9ab99f47612743bb41361a8cca8114999e52fca 100644
--- a/drivers/gpu/drm/radeon/radeon_vm.c
+++ b/drivers/gpu/drm/radeon/radeon_vm.c
@@ -595,7 +595,7 @@ int radeon_vm_update_page_directory(struct radeon_device *rdev,
 	ndw = 64;
 
 	/* assume the worst case */
-	ndw += vm->max_pde_used * 12;
+	ndw += vm->max_pde_used * 16;
 
 	/* update too big for an IB */
 	if (ndw > 0xfffff)