diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 8b0187019..42bb8ac00 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -94,7 +94,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        version:
+        compiler:
           - clang-3
           - clang-6
           - clang-8
diff --git a/samples/secure_tunneling/secure_tunnel/main.cpp b/samples/secure_tunneling/secure_tunnel/main.cpp
index e55b09243..4f39c3c10 100644
--- a/samples/secure_tunneling/secure_tunnel/main.cpp
+++ b/samples/secure_tunneling/secure_tunnel/main.cpp
@@ -16,7 +16,6 @@
 using namespace Aws::Crt;
 using namespace Aws::Iotsecuretunneling;
 using namespace Aws::Crt::Io;
-using namespace std::chrono_literals;
 
 void logMessage(std::shared_ptr<Message> message)
 {
@@ -352,7 +351,7 @@ int main(int argc, char *argv[])
      */
     while (keepRunning)
     {
-        std::this_thread::sleep_for(2000ms);
+        std::this_thread::sleep_for(std::chrono::milliseconds(2000));
         if (localProxyMode == AWS_SECURE_TUNNELING_SOURCE_MODE)
         {
             uint16_t messageCount = static_cast<uint16_t>(cmdData.input_count);
@@ -389,7 +388,7 @@ int main(int argc, char *argv[])
                     connectionId = 2;
                     secureTunnel->SendConnectionStart(m_serviceId.value(), connectionId);
 
-                    std::this_thread::sleep_for(2000ms);
+                    std::this_thread::sleep_for(std::chrono::milliseconds(2000));
                 }
                 else
                 {
@@ -399,7 +398,7 @@ int main(int argc, char *argv[])
         }
     }
 
-    std::this_thread::sleep_for(3000ms);
+    std::this_thread::sleep_for(std::chrono::milliseconds(3000));
 
     fprintf(stdout, "Closing Connection\n");
     // Set the Secure Tunnel Client to desire a stopped state
diff --git a/samples/secure_tunneling/tunnel_notification/main.cpp b/samples/secure_tunneling/tunnel_notification/main.cpp
index 66aa02453..a3f57ec15 100644
--- a/samples/secure_tunneling/tunnel_notification/main.cpp
+++ b/samples/secure_tunneling/tunnel_notification/main.cpp
@@ -184,7 +184,7 @@ int main(int argc, char *argv[])
 
     while (1)
     {
-        std::this_thread::sleep_for(500ms);
+        std::this_thread::sleep_for(std::chrono::milliseconds(500));
         continue;
     }
 }