diff --git a/libuavcan/test/protocol/data_type_info_provider.cpp b/libuavcan/test/protocol/data_type_info_provider.cpp
index 12ccb407e4..ccb458e9a6 100644
--- a/libuavcan/test/protocol/data_type_info_provider.cpp
+++ b/libuavcan/test/protocol/data_type_info_provider.cpp
@@ -113,6 +113,7 @@ TEST(DataTypeInfoProvider, Basic)
     ASSERT_LE(0, gdti_cln.call(1, gdti_request));
     nodes.spinBoth(MonotonicDuration::fromMSec(2));
 
+    ASSERT_TRUE(gdti_cln.collector.result.get());
     ASSERT_TRUE(gdti_cln.collector.result->isSuccessful());
     ASSERT_EQ(1, gdti_cln.collector.result->server_node_id.get());
     ASSERT_TRUE(gdti_cln.collector.result->response == GetDataTypeInfo::Response());  // Empty response
@@ -126,6 +127,7 @@ TEST(DataTypeInfoProvider, Basic)
     ASSERT_LE(0, cats_cln.call(1, cats_request));
     nodes.spinBoth(MonotonicDuration::fromMSec(2));
 
+    ASSERT_TRUE(gdti_cln.collector.result.get());
     ASSERT_TRUE(cats_cln.collector.result->isSuccessful());
     ASSERT_EQ(1, cats_cln.collector.result->server_node_id.get());
     ASSERT_EQ(NodeStatus::getDataTypeSignature().get(), cats_cln.collector.result->response.aggregate_signature);
@@ -141,6 +143,7 @@ TEST(DataTypeInfoProvider, Basic)
     ASSERT_LE(0, cats_cln.call(1, cats_request));
     nodes.spinBoth(MonotonicDuration::fromMSec(2));
 
+    ASSERT_TRUE(gdti_cln.collector.result.get());
     ASSERT_TRUE(cats_cln.collector.result->isSuccessful());
     ASSERT_EQ(0, cats_cln.collector.result->response.aggregate_signature);
     ASSERT_FALSE(cats_cln.collector.result->response.mutually_known_ids.any());
diff --git a/libuavcan/test/protocol/param_server.cpp b/libuavcan/test/protocol/param_server.cpp
index 0f90893344..afe5767390 100644
--- a/libuavcan/test/protocol/param_server.cpp
+++ b/libuavcan/test/protocol/param_server.cpp
@@ -106,6 +106,7 @@ TEST(ParamServer, Basic)
     uavcan::protocol::param::SaveErase::Request save_erase_rq;
     save_erase_rq.opcode = uavcan::protocol::param::SaveErase::Request::OPCODE_SAVE;
     doCall(save_erase_cln, save_erase_rq, nodes);
+    ASSERT_TRUE(save_erase_cln.collector.result.get());
     ASSERT_TRUE(save_erase_cln.collector.result->response.ok);
 
     save_erase_rq.opcode = uavcan::protocol::param::SaveErase::Request::OPCODE_ERASE;
@@ -123,6 +124,7 @@ TEST(ParamServer, Basic)
     uavcan::protocol::param::GetSet::Request get_set_rq;
     get_set_rq.name = "nonexistent_parameter";
     doCall(get_set_cln, get_set_rq, nodes);
+    ASSERT_TRUE(get_set_cln.collector.result.get());
     ASSERT_TRUE(get_set_cln.collector.result->response.name.empty());
 
     // No such variable, shall return empty name/value
diff --git a/libuavcan/test/protocol/restart_request_server.cpp b/libuavcan/test/protocol/restart_request_server.cpp
index 899d3256a9..d1900fe964 100644
--- a/libuavcan/test/protocol/restart_request_server.cpp
+++ b/libuavcan/test/protocol/restart_request_server.cpp
@@ -42,6 +42,7 @@ TEST(RestartRequestServer, Basic)
     ASSERT_LE(0, rrs_cln.call(1, request));
     nodes.spinBoth(uavcan::MonotonicDuration::fromMSec(2));
 
+    ASSERT_TRUE(rrs_cln.collector.result.get());
     ASSERT_TRUE(rrs_cln.collector.result->isSuccessful());
     ASSERT_FALSE(rrs_cln.collector.result->response.ok);
 
diff --git a/libuavcan/test/protocol/transport_stats_provider.cpp b/libuavcan/test/protocol/transport_stats_provider.cpp
index 13e365a8d1..27776ac81a 100644
--- a/libuavcan/test/protocol/transport_stats_provider.cpp
+++ b/libuavcan/test/protocol/transport_stats_provider.cpp
@@ -26,6 +26,7 @@ TEST(TransportStatsProvider, Basic)
     ASSERT_LE(0, tsp_cln.call(1, uavcan::protocol::GetTransportStats::Request()));
     ASSERT_LE(0, nodes.spinBoth(uavcan::MonotonicDuration::fromMSec(1)));
 
+    ASSERT_TRUE(tsp_cln.collector.result.get());
     ASSERT_TRUE(tsp_cln.collector.result->isSuccessful());
     ASSERT_EQ(0, tsp_cln.collector.result->response.transfer_errors);
     ASSERT_EQ(1, tsp_cln.collector.result->response.transfers_rx);
@@ -41,6 +42,7 @@ TEST(TransportStatsProvider, Basic)
     ASSERT_LE(0, tsp_cln.call(1, uavcan::protocol::GetTransportStats::Request()));
     ASSERT_LE(0, nodes.spinBoth(uavcan::MonotonicDuration::fromMSec(1)));
 
+    ASSERT_TRUE(tsp_cln.collector.result.get());
     ASSERT_EQ(0, tsp_cln.collector.result->response.transfer_errors);
     ASSERT_EQ(2, tsp_cln.collector.result->response.transfers_rx);
     ASSERT_EQ(1, tsp_cln.collector.result->response.transfers_tx);
@@ -71,6 +73,7 @@ TEST(TransportStatsProvider, Basic)
     ASSERT_LE(0, tsp_cln.call(1, uavcan::protocol::GetTransportStats::Request()));
     ASSERT_LE(0, nodes.spinBoth(uavcan::MonotonicDuration::fromMSec(1)));
 
+    ASSERT_TRUE(tsp_cln.collector.result.get());
     ASSERT_EQ(1, tsp_cln.collector.result->response.transfer_errors);                  // That broken frame
     ASSERT_EQ(3, tsp_cln.collector.result->response.transfers_rx);
     ASSERT_EQ(2, tsp_cln.collector.result->response.transfers_tx);