diff --git a/drivers/gpu/drm/qxl/qxl_prime.c b/drivers/gpu/drm/qxl/qxl_prime.c
index 3d031b50a8fd13dd8203f4de284ecedbb95ecbcc..9f029dda1f071431a9d90894096ab4a3f89bbe0a 100644
--- a/drivers/gpu/drm/qxl/qxl_prime.c
+++ b/drivers/gpu/drm/qxl/qxl_prime.c
@@ -68,5 +68,5 @@ int qxl_gem_prime_mmap(struct drm_gem_object *obj,
 		       struct vm_area_struct *area)
 {
 	WARN_ONCE(1, "not implemented");
-	return ENOSYS;
+	return -ENOSYS;
 }