diff --git a/src/corelib/time/qdatetime.h b/src/corelib/time/qdatetime.h
index 70a79a4f874..77247dcd078 100644
--- a/src/corelib/time/qdatetime.h
+++ b/src/corelib/time/qdatetime.h
@@ -543,10 +543,9 @@ public:
                 >;
             }
     {
-        const auto sysTime = std::chrono::clock_cast<std::chrono::system_clock>(time);
-        // clock_cast can change the duration, so convert it again to milliseconds
-        const auto timeInMSec = std::chrono::time_point_cast<std::chrono::milliseconds>(sysTime);
-        return fromStdTimePoint(timeInMSec);
+        using namespace std::chrono;
+        const sys_time<milliseconds> sysTime = clock_cast<system_clock>(time);
+        return fromStdTimePoint(sysTime);
     }
 #endif // __cpp_concepts