diff --git a/Tests/LibCore/TestLibCoreStream.cpp b/Tests/LibCore/TestLibCoreStream.cpp
index ebfc49c176..2f1276b49c 100644
--- a/Tests/LibCore/TestLibCoreStream.cpp
+++ b/Tests/LibCore/TestLibCoreStream.cpp
@@ -333,7 +333,7 @@ TEST_CASE(local_socket_read)
 
             return 0;
         },
-        [](int) {});
+        nullptr);
 
     event_loop.exec();
     ::unlink("/tmp/test-socket");
@@ -372,7 +372,7 @@ TEST_CASE(local_socket_write)
 
             return 0;
         },
-        [](int) {});
+        nullptr);
 
     event_loop.exec();
     ::unlink("/tmp/test-socket");