2 files changed, 5 insertions, 1 deletions
diff --git a/src/corelib/time/qdatetime.cpp b/src/corelib/time/qdatetime.cpp
index 6bf29bc0d6..9e58382aef 100644
--- a/src/corelib/time/qdatetime.cpp
+++ b/src/corelib/time/qdatetime.cpp
@@ -3618,6 +3618,7 @@ QDateTime::QDateTime() noexcept
     static_assert(sizeof(ShortData) == sizeof(qint64));
     static_assert(sizeof(Data) == sizeof(qint64));
 #endif
+    static_assert(sizeof(ShortData) >= sizeof(void*), "oops, Data::swap() is broken!");
 }
 
 /*!
diff --git a/src/corelib/time/qdatetime.h b/src/corelib/time/qdatetime.h
index 80227afde2..c1c67398a3 100644
--- a/src/corelib/time/qdatetime.h
+++ b/src/corelib/time/qdatetime.h
@@ -267,6 +267,9 @@ class Q_CORE_EXPORT QDateTime
         Data &operator=(const Data &other);
         ~Data();
 
+        void swap(Data &other) noexcept
+        { std::swap(data, other.data); }
+
         bool isShort() const;
         void detach();
 
@@ -290,7 +293,7 @@ public:
     QT_MOVE_ASSIGNMENT_OPERATOR_IMPL_VIA_PURE_SWAP(QDateTime)
     QDateTime &operator=(const QDateTime &other) noexcept;
 
-    void swap(QDateTime &other) noexcept { qSwap(d.d, other.d.d); }
+    void swap(QDateTime &other) noexcept { d.swap(other.d); }
 
     bool isNull() const;
     bool isValid() const;