diff --git a/drivers/infiniband/hw/mlx5/main.c b/drivers/infiniband/hw/mlx5/main.c
index b781ad74e6de..40c1a05c2445 100644
--- a/drivers/infiniband/hw/mlx5/main.c
+++ b/drivers/infiniband/hw/mlx5/main.c
@@ -888,7 +888,9 @@ static int mlx5_ib_query_device(struct ib_device *ibdev,
 		/* We support 'Gappy' memory registration too */
 		props->device_cap_flags |= IB_DEVICE_SG_GAPS_REG;
 	}
-	props->device_cap_flags |= IB_DEVICE_MEM_MGT_EXTENSIONS;
+	/* IB_WR_REG_MR always requires changing the entity size with UMR */
+	if (!MLX5_CAP_GEN(dev->mdev, umr_modify_entity_size_disabled))
+		props->device_cap_flags |= IB_DEVICE_MEM_MGT_EXTENSIONS;
 	if (MLX5_CAP_GEN(mdev, sho)) {
 		props->device_cap_flags |= IB_DEVICE_INTEGRITY_HANDOVER;
 		/* At this stage no support for signature handover */