diff --git a/plat/mediatek/drivers/iommu/mtk_iommu_smc.h b/plat/mediatek/drivers/iommu/mtk_iommu_smc.h
new file mode 100644
index 0000000..9537dbe
--- /dev/null
+++ b/plat/mediatek/drivers/iommu/mtk_iommu_smc.h
@@ -0,0 +1,15 @@
+/*
+ * Copyright (c) 2023, MediaTek Inc. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef IOMMU_SMC_H
+#define IOMMU_SMC_H
+
+#include <mtk_sip_svc.h>
+
+u_register_t mtk_iommu_handler(u_register_t x1, u_register_t x2,
+			u_register_t x3, u_register_t x4,
+			void *handle, struct smccc_res *smccc_ret);
+#endif