diff --git a/include/services/trp/trp_helpers.h b/include/services/trp/trp_helpers.h
index 8e786e2..83ec740 100644
--- a/include/services/trp/trp_helpers.h
+++ b/include/services/trp/trp_helpers.h
@@ -39,5 +39,12 @@
 
 __dead2 void trp_boot_abort(uint64_t err);
 
+/* TRP SMC result registers X0-X4 */
+#define TRP_SMC_RESULT_REGS	5
+
+struct trp_smc_result {
+	unsigned long long x[TRP_SMC_RESULT_REGS];
+};
+
 #endif /* __ASSEMBLER __ */
 #endif /* TRP_HELPERS_H */