diff --git a/drivers/gpu/drm/drm_hashtab.c b/drivers/gpu/drm/drm_hashtab.c
index 7b30b307674ba6d1b71065a6923758ea251d05b2..dae18e58e79be6870a7061c07ec6c4f90e0e848b 100644
--- a/drivers/gpu/drm/drm_hashtab.c
+++ b/drivers/gpu/drm/drm_hashtab.c
@@ -142,7 +142,7 @@ int drm_ht_just_insert_please(struct drm_open_hash *ht, struct drm_hash_item *it
 			      unsigned long add)
 {
 	int ret;
-	unsigned long mask = (1 << bits) - 1;
+	unsigned long mask = (1UL << bits) - 1;
 	unsigned long first, unshifted_key;
 
 	unshifted_key = hash_long(seed, bits);