diff --git a/Lts/DDS/DdsUnitTestsPlaceholder/ddsDataTopicTests_gtest.cpp b/Lts/DDS/DdsUnitTestsPlaceholder/ddsDataTopicTests_gtest.cpp
index 70d5d683f..f376692e6 100644
--- a/Lts/DDS/DdsUnitTestsPlaceholder/ddsDataTopicTests_gtest.cpp
+++ b/Lts/DDS/DdsUnitTestsPlaceholder/ddsDataTopicTests_gtest.cpp
@@ -10,7 +10,15 @@ TEST(DataTopicSmokeGTest, Format) {
 TEST(DataTopicSmokeGTest, MockDDSTopicFlow) {
   MockDDS::clear_all();
   MockDDS::publish("data/topic", "hello");
-  EXPECT_EQ(MockDDS::take_last("data/topic"), "hello");
+  auto r1 = MockDDS::take_last("data/topic");
+  auto p1 = r1.substr(r1.find(':') + 1);
+  EXPECT_EQ(p1, "hello");
   MockDDS::publish("data/topic", "world");
-  EXPECT_EQ(MockDDS::take_last("data/topic"), "world");
+  auto r2 = MockDDS::take_last("data/topic");
+  auto p2 = r2.substr(r2.find(':') + 1);
+  EXPECT_EQ(p2, "world");
+  // check sequence increment
+  auto s1 = std::stoul(r1.substr(0, r1.find(':')));
+  auto s2 = std::stoul(r2.substr(0, r2.find(':')));
+  EXPECT_LT(s1, s2);
 }
diff --git a/Lts/DDS/DdsUnitTestsPlaceholder/ddsFunctionTopicTests_gtest.cpp b/Lts/DDS/DdsUnitTestsPlaceholder/ddsFunctionTopicTests_gtest.cpp
index c6cdf3f5f..f27d3fa61 100644
--- a/Lts/DDS/DdsUnitTestsPlaceholder/ddsFunctionTopicTests_gtest.cpp
+++ b/Lts/DDS/DdsUnitTestsPlaceholder/ddsFunctionTopicTests_gtest.cpp
@@ -13,5 +13,8 @@ TEST(FunctionTopicSmokeGTest, MockDDSTopicAsSignal) {
   MockDDS::clear_all();
   MockDDS::publish("func/topic", "evt:1");
   auto val = MockDDS::take_last("func/topic");
-  EXPECT_EQ(val, "evt:1");
+  auto payload = val.substr(val.find(':') + 1);
+  EXPECT_EQ(payload, "evt:1");
+  auto seq = std::stoul(val.substr(0, val.find(':')));
+  EXPECT_EQ(seq, 1UL);
 }
diff --git a/Lts/DDS/DdsUnitTestsPlaceholder/ddsGenericDataTests_gtest.cpp b/Lts/DDS/DdsUnitTestsPlaceholder/ddsGenericDataTests_gtest.cpp
index 591cea5d8..eb37a782f 100644
--- a/Lts/DDS/DdsUnitTestsPlaceholder/ddsGenericDataTests_gtest.cpp
+++ b/Lts/DDS/DdsUnitTestsPlaceholder/ddsGenericDataTests_gtest.cpp
@@ -11,5 +11,11 @@ TEST(GenericSmokeGTest, MockDDSPublishReceive) {
   MockDDS::clear_all();
   MockDDS::publish("topic1", "payload42");
   auto r = MockDDS::take_last("topic1");
-  EXPECT_EQ(r, "payload42");
+  // format is "<seq>:<payload>"
+  auto pos = r.find(':');
+  ASSERT_NE(pos, std::string::npos);
+  auto seq = std::stoul(r.substr(0, pos));
+  auto payload = r.substr(pos + 1);
+  EXPECT_EQ(payload, "payload42");
+  EXPECT_EQ(seq, 1UL);
 }