diff --git a/tests/subsys/net/openthread/rpc/client/prj.conf b/tests/subsys/net/openthread/rpc/client/prj.conf
index d8dcaae7a2f6..0a0b1b621830 100644
--- a/tests/subsys/net/openthread/rpc/client/prj.conf
+++ b/tests/subsys/net/openthread/rpc/client/prj.conf
@@ -19,3 +19,5 @@ CONFIG_MOCK_NRF_RPC_TRANSPORT=y
 
 CONFIG_KERNEL_MEM_POOL=y
 CONFIG_HEAP_MEM_POOL_SIZE=4096
+
+CONFIG_ASAN=y
diff --git a/tests/subsys/net/openthread/rpc/server/prj.conf b/tests/subsys/net/openthread/rpc/server/prj.conf
index 6f9184baa8fc..22a1be9c75c1 100644
--- a/tests/subsys/net/openthread/rpc/server/prj.conf
+++ b/tests/subsys/net/openthread/rpc/server/prj.conf
@@ -18,3 +18,5 @@ CONFIG_MOCK_NRF_RPC_TRANSPORT=y
 
 CONFIG_KERNEL_MEM_POOL=y
 CONFIG_HEAP_MEM_POOL_SIZE=4096
+
+CONFIG_ASAN=y
diff --git a/tests/subsys/net/openthread/rpc/server/src/ip6_suite.c b/tests/subsys/net/openthread/rpc/server/src/ip6_suite.c
index c5d88d48bc5b..d4108aee065f 100644
--- a/tests/subsys/net/openthread/rpc/server/src/ip6_suite.c
+++ b/tests/subsys/net/openthread/rpc/server/src/ip6_suite.c
@@ -136,72 +136,99 @@ ZTEST(ot_rpc_ip6, test_otIp6IsEnabled_true)
  * Test reception of otIp6SubscribeMulticastAddress(ff02::1) command.
  * Test serialization of the result: OT_ERROR_NONE.
  */
-ZTEST(ot_rpc_ip6, test_otIp6SubscribeMulticastAddress)
+static otError subscribe_multicast_ff02_1_fake(otInstance *instance, const otIp6Address *addr)
 {
-	const otIp6Address addr = {.mFields.m8 = {MADDR_FF02_1}};
+	const otIp6Address exp_addr = {.mFields.m8 = {MADDR_FF02_1}};
+
+	zassert_mem_equal(addr, &exp_addr, sizeof(exp_addr));
+
+	return OT_ERROR_NONE;
+}
 
-	otIp6SubscribeMulticastAddress_fake.return_val = OT_ERROR_NONE;
+ZTEST(ot_rpc_ip6, test_otIp6SubscribeMulticastAddress)
+{
+	otIp6SubscribeMulticastAddress_fake.custom_fake = subscribe_multicast_ff02_1_fake;
 
 	mock_nrf_rpc_tr_expect_add(RPC_RSP(0x00), NO_RSP);
 	mock_nrf_rpc_tr_receive(RPC_CMD(OT_RPC_CMD_IP6_SUBSCRIBE_MADDR, 0x50, MADDR_FF02_1));
 	mock_nrf_rpc_tr_expect_done();
 
 	zassert_equal(otIp6SubscribeMulticastAddress_fake.call_count, 1);
-	zassert_mem_equal(otIp6SubscribeMulticastAddress_fake.arg1_val, &addr, sizeof(addr));
 }
 
 /*
  * Test reception of otIp6SubscribeMulticastAddress(ff02::1) command.
  * Test serialization of the result: OT_ERROR_FAILED.
  */
-ZTEST(ot_rpc_ip6, test_otIp6SubscribeMulticastAddress_failed)
+static otError subscribe_multicast_ff02_1_failed_fake(otInstance *instance,
+						      const otIp6Address *addr)
 {
-	const otIp6Address addr = {.mFields.m8 = {MADDR_FF02_1}};
+	const otIp6Address exp_addr = {.mFields.m8 = {MADDR_FF02_1}};
+
+	zassert_mem_equal(addr, &exp_addr, sizeof(exp_addr));
+
+	return OT_ERROR_FAILED;
+}
 
-	otIp6SubscribeMulticastAddress_fake.return_val = OT_ERROR_FAILED;
+ZTEST(ot_rpc_ip6, test_otIp6SubscribeMulticastAddress_failed)
+{
+	otIp6SubscribeMulticastAddress_fake.custom_fake = subscribe_multicast_ff02_1_failed_fake;
 
 	mock_nrf_rpc_tr_expect_add(RPC_RSP(0x01), NO_RSP);
 	mock_nrf_rpc_tr_receive(RPC_CMD(OT_RPC_CMD_IP6_SUBSCRIBE_MADDR, 0x50, MADDR_FF02_1));
 	mock_nrf_rpc_tr_expect_done();
 
 	zassert_equal(otIp6SubscribeMulticastAddress_fake.call_count, 1);
-	zassert_mem_equal(otIp6SubscribeMulticastAddress_fake.arg1_val, &addr, sizeof(addr));
 }
 
 /*
  * Test reception of otIp6UnubscribeMulticastAddress(ff02::1) command.
  * Test serialization of the result: OT_ERROR_NONE.
  */
-ZTEST(ot_rpc_ip6, test_otIp6UnsubscribeMulticastAddress)
+static otError unsubscribe_multicast_ff02_1_fake(otInstance *instance, const otIp6Address *addr)
 {
-	const otIp6Address addr = {.mFields.m8 = {MADDR_FF02_1}};
+	const otIp6Address exp_addr = {.mFields.m8 = {MADDR_FF02_1}};
+
+	zassert_mem_equal(addr, &exp_addr, sizeof(exp_addr));
+
+	return OT_ERROR_NONE;
+}
 
-	otIp6UnsubscribeMulticastAddress_fake.return_val = OT_ERROR_NONE;
+ZTEST(ot_rpc_ip6, test_otIp6UnsubscribeMulticastAddress)
+{
+	otIp6UnsubscribeMulticastAddress_fake.custom_fake = unsubscribe_multicast_ff02_1_fake;
 
 	mock_nrf_rpc_tr_expect_add(RPC_RSP(0x00), NO_RSP);
 	mock_nrf_rpc_tr_receive(RPC_CMD(OT_RPC_CMD_IP6_UNSUBSCRIBE_MADDR, 0x50, MADDR_FF02_1));
 	mock_nrf_rpc_tr_expect_done();
 
 	zassert_equal(otIp6UnsubscribeMulticastAddress_fake.call_count, 1);
-	zassert_mem_equal(otIp6UnsubscribeMulticastAddress_fake.arg1_val, &addr, sizeof(addr));
 }
 
 /*
  * Test reception of otIp6UnubscribeMulticastAddress(ff02::1) command.
  * Test serialization of the result: OT_ERROR_FAILED.
  */
-ZTEST(ot_rpc_ip6, test_otIp6UnsubscribeMulticastAddress_failed)
+static otError unsubscribe_multicast_ff02_1_failed_fake(otInstance *instance,
+							const otIp6Address *addr)
 {
-	const otIp6Address addr = {.mFields.m8 = {MADDR_FF02_1}};
+	const otIp6Address exp_addr = {.mFields.m8 = {MADDR_FF02_1}};
+
+	zassert_mem_equal(addr, &exp_addr, sizeof(exp_addr));
+
+	return OT_ERROR_FAILED;
+}
 
-	otIp6UnsubscribeMulticastAddress_fake.return_val = OT_ERROR_FAILED;
+ZTEST(ot_rpc_ip6, test_otIp6UnsubscribeMulticastAddress_failed)
+{
+	otIp6UnsubscribeMulticastAddress_fake.custom_fake =
+		unsubscribe_multicast_ff02_1_failed_fake;
 
 	mock_nrf_rpc_tr_expect_add(RPC_RSP(0x01), NO_RSP);
 	mock_nrf_rpc_tr_receive(RPC_CMD(OT_RPC_CMD_IP6_UNSUBSCRIBE_MADDR, 0x50, MADDR_FF02_1));
 	mock_nrf_rpc_tr_expect_done();
 
 	zassert_equal(otIp6UnsubscribeMulticastAddress_fake.call_count, 1);
-	zassert_mem_equal(otIp6UnsubscribeMulticastAddress_fake.arg1_val, &addr, sizeof(addr));
 }
 
 /*
diff --git a/tests/subsys/net/openthread/rpc/server/src/message_suite.c b/tests/subsys/net/openthread/rpc/server/src/message_suite.c
index da838767393f..12567cee4730 100644
--- a/tests/subsys/net/openthread/rpc/server/src/message_suite.c
+++ b/tests/subsys/net/openthread/rpc/server/src/message_suite.c
@@ -43,6 +43,15 @@ static void tc_setup(void *f)
 	FFF_RESET_HISTORY();
 }
 
+static otMessage *udp_new_message_failed_fake(otInstance *instance,
+					      const otMessageSettings *settings)
+{
+	zassert_true(settings->mLinkSecurityEnabled);
+	zassert_equal(settings->mPriority, 40);
+
+	return NULL;
+}
+
 ZTEST(ot_rpc_message, test_otUdpNewMessage_failing)
 {
 	const uint8_t prio = 40;
@@ -52,15 +61,24 @@ ZTEST(ot_rpc_message, test_otUdpNewMessage_failing)
 	mock_nrf_rpc_tr_expect_add(RPC_RSP(0), NO_RSP);
 	mock_nrf_rpc_tr_receive(RPC_CMD(OT_RPC_CMD_UDP_NEW_MESSAGE, CBOR_NULL));
 
+	zassert_equal(otUdpNewMessage_fake.call_count, 1);
 	zassert_is_null(otUdpNewMessage_fake.arg1_val);
 
+	otUdpNewMessage_fake.custom_fake = udp_new_message_failed_fake;
+
 	mock_nrf_rpc_tr_expect_add(RPC_RSP(0), NO_RSP);
 	mock_nrf_rpc_tr_receive(RPC_CMD(OT_RPC_CMD_UDP_NEW_MESSAGE, CBOR_TRUE, CBOR_UINT8(prio)));
 	mock_nrf_rpc_tr_expect_done();
 
 	zassert_equal(otUdpNewMessage_fake.call_count, 2);
-	zassert_true(otUdpNewMessage_fake.arg1_val->mLinkSecurityEnabled);
-	zassert_equal(otUdpNewMessage_fake.arg1_val->mPriority, prio);
+}
+
+static otMessage *udp_new_message_free_fake(otInstance *instance, const otMessageSettings *settings)
+{
+	zassert_true(settings->mLinkSecurityEnabled);
+	zassert_equal(settings->mPriority, 40);
+
+	return (otMessage *)1;
 }
 
 ZTEST(ot_rpc_message, test_otUdpNewMessage_free_working)
@@ -72,14 +90,15 @@ ZTEST(ot_rpc_message, test_otUdpNewMessage_free_working)
 	mock_nrf_rpc_tr_expect_add(RPC_RSP(1), NO_RSP);
 	mock_nrf_rpc_tr_receive(RPC_CMD(OT_RPC_CMD_UDP_NEW_MESSAGE, CBOR_NULL));
 
+	zassert_equal(otUdpNewMessage_fake.call_count, 1);
 	zassert_is_null(otUdpNewMessage_fake.arg1_val);
 
+	otUdpNewMessage_fake.custom_fake = udp_new_message_free_fake;
+
 	mock_nrf_rpc_tr_expect_add(RPC_RSP(2), NO_RSP);
 	mock_nrf_rpc_tr_receive(RPC_CMD(OT_RPC_CMD_UDP_NEW_MESSAGE, CBOR_TRUE, CBOR_UINT8(prio)));
 
 	zassert_equal(otUdpNewMessage_fake.call_count, 2);
-	zassert_true(otUdpNewMessage_fake.arg1_val->mLinkSecurityEnabled);
-	zassert_equal(otUdpNewMessage_fake.arg1_val->mPriority, prio);
 
 	mock_nrf_rpc_tr_expect_add(RPC_RSP(), NO_RSP);
 	mock_nrf_rpc_tr_receive(RPC_CMD(OT_RPC_CMD_MESSAGE_FREE, 1));
diff --git a/tests/subsys/net/openthread/rpc/server/src/netdiag_suite.c b/tests/subsys/net/openthread/rpc/server/src/netdiag_suite.c
index 87e8d676d0db..1509bd7637cf 100644
--- a/tests/subsys/net/openthread/rpc/server/src/netdiag_suite.c
+++ b/tests/subsys/net/openthread/rpc/server/src/netdiag_suite.c
@@ -50,25 +50,28 @@ static void tc_setup(void *f)
 #define TEST_STRING_SETTER(test_name, cmd, data, data_cbor, func_to_call, max_length, result_exp)  \
 	static otError fake_##test_name(otInstance *instance, const char *arg)                     \
 	{                                                                                          \
+		char data_exp[] = data;                                                            \
+                                                                                                   \
 		ARG_UNUSED(instance);                                                              \
+                                                                                                   \
 		if (strlen(arg) > max_length) {                                                    \
 			return OT_ERROR_INVALID_ARGS;                                              \
 		}                                                                                  \
                                                                                                    \
+		zassert_str_equal(func_to_call##_fake.arg1_val, data_exp);                         \
+                                                                                                   \
 		return OT_ERROR_NONE;                                                              \
 	}                                                                                          \
-												   \
+                                                                                                   \
 	ZTEST(ot_rpc_netdiag, test_name)                                                           \
 	{                                                                                          \
-		char data_exp[] = data;                                                            \
 		func_to_call##_fake.custom_fake = fake_##test_name;                                \
-												   \
+                                                                                                   \
 		mock_nrf_rpc_tr_expect_add(RPC_RSP(result_exp), NO_RSP);                           \
 		mock_nrf_rpc_tr_receive(RPC_CMD(cmd, data_cbor));                                  \
 		mock_nrf_rpc_tr_expect_done();                                                     \
-												   \
+                                                                                                   \
 		zassert_equal(func_to_call##_fake.call_count, 1);                                  \
-		zassert_str_equal(func_to_call##_fake.arg1_val, data_exp);                         \
 	}
 
 #define TEST_STRING_GETTER(test_name, cmd, data, data_cbor, func_to_call)                          \