diff --git a/spm/cactus/cactus_main.c b/spm/cactus/cactus_main.c
index cb83d87..9388ec5 100644
--- a/spm/cactus/cactus_main.c
+++ b/spm/cactus/cactus_main.c
@@ -97,7 +97,7 @@
 			 * If execution gets to this point means all operations
 			 * with memory retrieval went well, as such replying
 			 */
-			ffa_ret = cactus_success_resp(vm_id, source);
+			ffa_ret = cactus_success_resp(vm_id, source, 0);
 			break;
 		case CACTUS_REQ_MEM_SEND_CMD:
 		{
@@ -137,14 +137,14 @@
 			if (!is_ffa_direct_response(ffa_ret)) {
 				ERROR("Failed to send message. error: %x\n",
 					ffa_error_code(ffa_ret));
-				ffa_ret = cactus_error_resp(vm_id, source);
+				ffa_ret = cactus_error_resp(vm_id, source, 0);
 				break;
 			}
 
 			/* If anything went bad on the receiver's end. */
 			if (cactus_get_response(ffa_ret) == CACTUS_ERROR) {
 				ERROR("Received error from receiver!\n");
-				ffa_ret = cactus_error_resp(vm_id, source);
+				ffa_ret = cactus_error_resp(vm_id, source, 0);
 				break;
 			}
 
@@ -159,7 +159,7 @@
 							.ret0 == FFA_ERROR) {
 					ERROR("Failed to reclaim memory!\n");
 					ffa_ret = cactus_error_resp(vm_id,
-								    source);
+								    source, 0);
 					break;
 				}
 
@@ -181,7 +181,7 @@
 				#endif
 			}
 
-			ffa_ret = cactus_success_resp(vm_id, source);
+			ffa_ret = cactus_success_resp(vm_id, source, 0);
 			break;
 		}
 		case CACTUS_ECHO_CMD:
@@ -217,8 +217,9 @@
 				success = false;
 			}
 
-			ffa_ret = success ? cactus_success_resp(vm_id, source) :
-					    cactus_error_resp(vm_id, source);
+			ffa_ret = success ?
+				  cactus_success_resp(vm_id, source, 0) :
+				  cactus_error_resp(vm_id, source, 0);
 			break;
 		}
 		case CACTUS_DEADLOCK_CMD:
@@ -273,18 +274,18 @@
 				 * created the deadlock. As such, reply back
 				 * to the partitions.
 				 */
-				ffa_ret = cactus_success_resp(vm_id, source);
+				ffa_ret = cactus_success_resp(vm_id, source, 0);
 				break;
 			}
 
 			/* Shouldn't get to this point */
 			ERROR("Deadlock test went wrong!\n");
-			ffa_ret = cactus_error_resp(vm_id, source);
+			ffa_ret = cactus_error_resp(vm_id, source, 0);
 			break;
 		}
 		case CACTUS_REQ_SIMD_FILL_CMD:
 			fill_simd_vectors();
-			ffa_ret = cactus_success_resp(vm_id, source);
+			ffa_ret = cactus_success_resp(vm_id, source, 0);
 			break;
 		default:
 			/*
diff --git a/spm/cactus/cactus_test_cmds.h b/spm/cactus/cactus_test_cmds.h
index c662d27..f814ba5 100644
--- a/spm/cactus/cactus_test_cmds.h
+++ b/spm/cactus/cactus_test_cmds.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2020-2021, Arm Limited. All rights reserved.
+ * Copyright (c) 2021, Arm Limited. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -36,6 +36,63 @@
 						val2, val3);
 }
 
+/**
+ * Template for responses to Cactus commands.
+ * 'cactus_send_response' is the template for custom responses, in case there is
+ * a need to propagate more than one value in the response of a command.
+ */
+static inline smc_ret_values cactus_send_response(
+	ffa_vm_id_t source, ffa_vm_id_t dest, uint32_t resp, uint32_t val0,
+	uint64_t val1, uint64_t val2, uint64_t val3)
+{
+	return ffa_msg_send_direct_resp64_5args(source, dest, resp, val0, val1,
+						val2, val3);
+}
+
+/**
+ * For responses of one value only.
+ */
+static inline smc_ret_values cactus_response(
+	ffa_vm_id_t source, ffa_vm_id_t dest, uint32_t response)
+{
+	return ffa_msg_send_direct_resp(source, dest, response);
+}
+
+static inline uint32_t cactus_get_response(smc_ret_values ret)
+{
+	return (uint32_t)ret.ret3;
+}
+
+/**
+ * In a successful test, in case the SP needs to propagate an extra value
+ * to conclude the test.
+ * If more arguments are needed, a custom response should be defined for the
+ * specific test.
+ */
+static inline smc_ret_values cactus_success_resp(
+		ffa_vm_id_t source, ffa_vm_id_t dest, uint64_t value)
+{
+	return cactus_send_response(source, dest, CACTUS_SUCCESS, value,
+				    0, 0, 0);
+}
+
+/**
+ * In case the test fails on the SP side, the 'error_code' should help specify
+ * the reason, which can be specific to the test, or general ones as defined
+ * in the error code list.
+ */
+static inline smc_ret_values cactus_error_resp(
+		ffa_vm_id_t source, ffa_vm_id_t dest, uint32_t error_code)
+{
+	return cactus_send_response(source, dest, CACTUS_ERROR, error_code,
+				    0, 0, 0);
+}
+
+static inline uint32_t cactus_error_code(smc_ret_values ret)
+{
+	return (uint32_t) ret.ret4;
+}
+
 #define PRINT_CMD(smc_ret)						\
 	VERBOSE("cmd %lx; args: %lx, %lx, %lx, %lx\n",	 		\
 		smc_ret.ret3, smc_ret.ret4, smc_ret.ret5, 		\
@@ -189,30 +246,4 @@
 	return cactus_send_cmd(source, dest, CACTUS_REQ_SIMD_FILL_CMD, 0, 0, 0, 0);
 }
 
-/**
- * Template for responses to CACTUS commands.
- */
-static inline smc_ret_values cactus_response(
-	ffa_vm_id_t source, ffa_vm_id_t dest, uint32_t response)
-{
-	return ffa_msg_send_direct_resp(source, dest, response);
-}
-
-static inline smc_ret_values cactus_success_resp(
-		ffa_vm_id_t source, ffa_vm_id_t dest)
-{
-	return cactus_response(source, dest, CACTUS_SUCCESS);
-}
-
-static inline smc_ret_values cactus_error_resp(
-		ffa_vm_id_t source, ffa_vm_id_t dest)
-{
-	return cactus_response(source, dest, CACTUS_ERROR);
-}
-
-static inline uint32_t cactus_get_response(smc_ret_values ret)
-{
-	return (uint32_t)ret.ret3;
-}
-
 #endif