diff --git a/plat/intel/soc/common/include/socfpga_sip_svc.h b/plat/intel/soc/common/include/socfpga_sip_svc.h
index 6bb41f3..2b1d983 100644
--- a/plat/intel/soc/common/include/socfpga_sip_svc.h
+++ b/plat/intel/soc/common/include/socfpga_sip_svc.h
@@ -28,6 +28,7 @@
 #define INTEL_SIP_LEGACY_SMC_ECC_DBE			0xC200000D
 #define INTEL_SIP_SMC_RSU_NOTIFY			0xC200000E
 #define INTEL_SIP_SMC_RSU_RETRY_COUNTER			0xC200000F
+#define INTEL_SIP_SMC_MBOX_SEND_CMD			0xC200001E
 
 /* FPGA config helpers */
 #define INTEL_SIP_SMC_FPGA_CONFIG_ADDR			0x400000