diff --git a/drivers/infiniband/hw/mlx5/main.c b/drivers/infiniband/hw/mlx5/main.c
index 24f5f48..29878aa 100644
--- a/drivers/infiniband/hw/mlx5/main.c
+++ b/drivers/infiniband/hw/mlx5/main.c
@@ -472,7 +472,7 @@
 }
 
 struct mlx5_reg_node_desc {
-	u8	desc[64];
+	u8	desc[IB_DEVICE_NODE_DESC_MAX];
 };
 
 static int mlx5_query_node_desc(struct mlx5_ib_dev *dev, char *node_desc)
@@ -920,13 +920,13 @@
 	 * If possible, pass node desc to FW, so it can generate
 	 * a 144 trap.  If cmd fails, just ignore.
 	 */
-	memcpy(&in, props->node_desc, 64);
+	memcpy(&in, props->node_desc, IB_DEVICE_NODE_DESC_MAX);
 	err = mlx5_core_access_reg(dev->mdev, &in, sizeof(in), &out,
 				   sizeof(out), MLX5_REG_NODE_DESC, 0, 1);
 	if (err)
 		return err;
 
-	memcpy(ibdev->node_desc, props->node_desc, 64);
+	memcpy(ibdev->node_desc, props->node_desc, IB_DEVICE_NODE_DESC_MAX);
 
 	return err;
 }