diff --git a/tests/Mqtt5ClientTest.cpp b/tests/Mqtt5ClientTest.cpp
index ab53a042c..00b56e339 100644
--- a/tests/Mqtt5ClientTest.cpp
+++ b/tests/Mqtt5ClientTest.cpp
@@ -2061,7 +2061,7 @@ static int s_TestMqtt5SharedSubscriptionTest(Aws::Crt::Allocator *allocator, voi
     subscribe->WithSubscription(std::move(subscription));
 
     std::promise<void> suback;
-    auto onSubAck = [&](int , std::shared_ptr<SubAckPacket>) { suback.set_value(); };
+    auto onSubAck = [&](int, std::shared_ptr<SubAckPacket>) { suback.set_value(); };
 
     /*subscribe both clients */
     ASSERT_TRUE(mqtt5Client->Subscribe(subscribe, onSubAck));