diff --git a/drivers/iommu/mtk_iommu_v1.c b/drivers/iommu/mtk_iommu_v1.c
index 96d30111c34ea83fe0ae17cc6d2418ac2e2f60aa..3ddac0078a2be5e195f424aa7a57b186022e40c8 100644
--- a/drivers/iommu/mtk_iommu_v1.c
+++ b/drivers/iommu/mtk_iommu_v1.c
@@ -440,6 +440,10 @@ static int mtk_iommu_add_device(struct device *dev)
 		iommu_spec.args_count = count;
 
 		mtk_iommu_create_mapping(dev, &iommu_spec);
+
+		/* dev->iommu_fwspec might have changed */
+		fwspec = dev_iommu_fwspec_get(dev);
+
 		of_node_put(iommu_spec.np);
 	}