diff --git a/drivers/net/ethernet/mellanox/mlx4/en_tx.c b/drivers/net/ethernet/mellanox/mlx4/en_tx.c
index 8a32a8f7f9c0c7316665294b5342051b46f8b623..2cc82dc073974212f156583a5490dd26a54ddfef 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_tx.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_tx.c
@@ -718,7 +718,7 @@ void mlx4_en_xmit_doorbell(struct mlx4_en_tx_ring *ring)
 #else
 	iowrite32be(
 #endif
-		  ring->doorbell_qpn,
+		  (__force u32)ring->doorbell_qpn,
 		  ring->bf.uar->map + MLX4_SEND_DOORBELL);
 }