diff --git a/src/corelib/kernel/qcore_foundation.mm b/src/corelib/kernel/qcore_foundation.mm
index 2291017a5d..f5ccd1c1f2 100644
--- a/src/corelib/kernel/qcore_foundation.mm
+++ b/src/corelib/kernel/qcore_foundation.mm
@@ -375,8 +375,8 @@ QDateTime QDateTime::fromCFDate(CFDateRef date)
 {
     if (!date)
         return QDateTime();
-    return QDateTime::fromMSecsSinceEpoch(static_cast<qint64>((CFDateGetAbsoluteTime(date)
-                                                    + kCFAbsoluteTimeIntervalSince1970) * 1000));
+    CFAbsoluteTime sSinceEpoch = kCFAbsoluteTimeIntervalSince1970 + CFDateGetAbsoluteTime(date);
+    return QDateTime::fromMSecsSinceEpoch(qRound64(sSinceEpoch * 1000));
 }
 
 /*!
@@ -404,7 +404,7 @@ QDateTime QDateTime::fromNSDate(const NSDate *date)
 {
     if (!date)
         return QDateTime();
-    return QDateTime::fromMSecsSinceEpoch(static_cast<qint64>([date timeIntervalSince1970] * 1000));
+    return QDateTime::fromMSecsSinceEpoch(qRound64([date timeIntervalSince1970] * 1000));
 }
 
 /*!
diff --git a/tests/auto/corelib/tools/qdatetime/tst_qdatetime_mac.mm b/tests/auto/corelib/tools/qdatetime/tst_qdatetime_mac.mm
index fb49b8952e..f73c7b9d5d 100644
--- a/tests/auto/corelib/tools/qdatetime/tst_qdatetime_mac.mm
+++ b/tests/auto/corelib/tools/qdatetime/tst_qdatetime_mac.mm
@@ -36,8 +36,11 @@
 void tst_QDateTime_macTypes()
 {
     // QDateTime <-> CFDate
-    {
-        QDateTime qtDateTime = QDateTime::fromMSecsSinceEpoch(0);
+
+    static const int kMsPerSecond = 1000;
+
+    for (int i = 0; i < kMsPerSecond; ++i) {
+        QDateTime qtDateTime = QDateTime::fromMSecsSinceEpoch(i);
         const CFDateRef cfDate = qtDateTime.toCFDate();
         QCOMPARE(QDateTime::fromCFDate(cfDate), qtDateTime);
         CFRelease(cfDate);
@@ -50,9 +53,9 @@ void tst_QDateTime_macTypes()
         QCOMPARE(QDateTime::fromCFDate(cfDate), qtDateTimeCopy);
     }
     // QDateTime <-> NSDate
-    {
+    for (int i = 0; i < kMsPerSecond; ++i) {
         QMacAutoReleasePool pool;
-        QDateTime qtDateTime = QDateTime::fromMSecsSinceEpoch(0);
+        QDateTime qtDateTime = QDateTime::fromMSecsSinceEpoch(i);
         const NSDate *nsDate = qtDateTime.toNSDate();
         QCOMPARE(QDateTime::fromNSDate(nsDate), qtDateTime);
     }