diff --git a/src/corelib/global/qflags.h b/src/corelib/global/qflags.h
index 6332e2d761cac1893a5db0bed106715b97fca2dd..5b7edbafa6fdfa08de23a28463672735b1206c3a 100644
--- a/src/corelib/global/qflags.h
+++ b/src/corelib/global/qflags.h
@@ -97,31 +97,32 @@ public:
     inline QFlags(const QFlags &other);
     inline QFlags &operator=(const QFlags &other);
 #endif
-    Q_DECL_CONSTEXPR inline QFlags(Enum f) : i(f) {}
+    Q_DECL_CONSTEXPR inline QFlags(Enum f) : i(Int(f)) {}
     Q_DECL_CONSTEXPR inline QFlags(Zero = 0) : i(0) {}
     Q_DECL_CONSTEXPR inline QFlags(QFlag f) : i(f) {}
 
     inline QFlags &operator&=(int mask) { i &= mask; return *this; }
     inline QFlags &operator&=(uint mask) { i &= mask; return *this; }
+    inline QFlags &operator&=(Enum mask) { i &= Int(mask); return *this; }
     inline QFlags &operator|=(QFlags f) { i |= f.i; return *this; }
-    inline QFlags &operator|=(Enum f) { i |= f; return *this; }
+    inline QFlags &operator|=(Enum f) { i |= Int(f); return *this; }
     inline QFlags &operator^=(QFlags f) { i ^= f.i; return *this; }
-    inline QFlags &operator^=(Enum f) { i ^= f; return *this; }
+    inline QFlags &operator^=(Enum f) { i ^= Int(f); return *this; }
 
     Q_DECL_CONSTEXPR  inline operator Int() const { return i; }
 
     Q_DECL_CONSTEXPR inline QFlags operator|(QFlags f) const { return QFlags(Enum(i | f.i)); }
-    Q_DECL_CONSTEXPR inline QFlags operator|(Enum f) const { return QFlags(Enum(i | f)); }
+    Q_DECL_CONSTEXPR inline QFlags operator|(Enum f) const { return QFlags(Enum(i | Int(f))); }
     Q_DECL_CONSTEXPR inline QFlags operator^(QFlags f) const { return QFlags(Enum(i ^ f.i)); }
-    Q_DECL_CONSTEXPR inline QFlags operator^(Enum f) const { return QFlags(Enum(i ^ f)); }
+    Q_DECL_CONSTEXPR inline QFlags operator^(Enum f) const { return QFlags(Enum(i ^ Int(f))); }
     Q_DECL_CONSTEXPR inline QFlags operator&(int mask) const { return QFlags(Enum(i & mask)); }
     Q_DECL_CONSTEXPR inline QFlags operator&(uint mask) const { return QFlags(Enum(i & mask)); }
-    Q_DECL_CONSTEXPR inline QFlags operator&(Enum f) const { return QFlags(Enum(i & f)); }
+    Q_DECL_CONSTEXPR inline QFlags operator&(Enum f) const { return QFlags(Enum(i & Int(f))); }
     Q_DECL_CONSTEXPR inline QFlags operator~() const { return QFlags(Enum(~i)); }
 
     Q_DECL_CONSTEXPR inline bool operator!() const { return !i; }
 
-    Q_DECL_CONSTEXPR inline bool testFlag(Enum f) const { return (i & f) == f && (f != 0 || i == Int(f) ); }
+    Q_DECL_CONSTEXPR inline bool testFlag(Enum f) const { return (i & Int(f)) == Int(f) && (Int(f) != 0 || i == Int(f) ); }
 private:
     Int i;
 };
diff --git a/src/corelib/global/qglobal.cpp b/src/corelib/global/qglobal.cpp
index 4134dd67003f4ee274348991ac3c733030ff4988..4598f60d5e87735a3943bce74f81902b96d0d01a 100644
--- a/src/corelib/global/qglobal.cpp
+++ b/src/corelib/global/qglobal.cpp
@@ -239,6 +239,12 @@ Q_CORE_EXPORT void *qMemSet(void *dest, int c, size_t n);
     \overload
 */
 
+/*!
+    \fn QFlags &QFlags::operator&=(Enum mask)
+
+    \overload
+*/
+
 /*!
     \fn QFlags &QFlags::operator|=(QFlags other)
 
diff --git a/src/corelib/io/qdebug.h b/src/corelib/io/qdebug.h
index ce72fcd26d01f45981695064fe3cc3e471f3ae2b..9ed5f6e9514098c1f89114f874b76e30321f9222 100644
--- a/src/corelib/io/qdebug.h
+++ b/src/corelib/io/qdebug.h
@@ -280,7 +280,7 @@ inline QDebug operator<<(QDebug debug, const QFlags<T> &flags)
                 debug.nospace() << '|';
             else
                 needSeparator = true;
-            debug.nospace() << "0x" << QByteArray::number(T(1 << i), 16).constData();
+            debug.nospace() << "0x" << QByteArray::number(typename QFlags<T>::Int(1) << i, 16).constData();
         }
     }
     debug << ')';
diff --git a/tests/auto/corelib/global/qflags/tst_qflags.cpp b/tests/auto/corelib/global/qflags/tst_qflags.cpp
index b9b817d688280f91b1c1532af67a493984d8e752..e50a6b63fea18ce01636d9ab66cc34d1f23e363e 100644
--- a/tests/auto/corelib/global/qflags/tst_qflags.cpp
+++ b/tests/auto/corelib/global/qflags/tst_qflags.cpp
@@ -49,6 +49,7 @@ private slots:
     void testFlagMultiBits() const;
     void constExpr();
     void signedness();
+    void classEnum();
 };
 
 void tst_QFlags::testFlag() const
@@ -137,6 +138,121 @@ void tst_QFlags::signedness()
                      QtPrivate::is_signed<Qt::Alignment::Int>::value));
 }
 
+#if defined(Q_COMPILER_CLASS_ENUM)
+enum class MyStrictEnum { StrictZero, StrictOne, StrictTwo, StrictFour=4 };
+Q_DECLARE_FLAGS( MyStrictFlags, MyStrictEnum )
+Q_DECLARE_OPERATORS_FOR_FLAGS( MyStrictFlags )
+
+Q_STATIC_ASSERT( !QTypeInfo<MyStrictFlags>::isComplex );
+Q_STATIC_ASSERT( !QTypeInfo<MyStrictFlags>::isStatic );
+Q_STATIC_ASSERT( !QTypeInfo<MyStrictFlags>::isLarge );
+Q_STATIC_ASSERT( !QTypeInfo<MyStrictFlags>::isPointer );
+#endif
+
+void tst_QFlags::classEnum()
+{
+#if defined(Q_COMPILER_CLASS_ENUM)
+    // The main aim of the test is making sure it compiles
+    // The QCOMPARE are there as an extra
+    MyStrictEnum e1 = MyStrictEnum::StrictOne;
+    MyStrictEnum e2 = MyStrictEnum::StrictTwo;
+
+    MyStrictFlags f1(MyStrictEnum::StrictOne);
+    QCOMPARE(f1, 1);
+
+    MyStrictFlags f2(e2);
+    QCOMPARE(f2, 2);
+
+    MyStrictFlags f0;
+    QCOMPARE(f0, 0);
+
+    MyStrictFlags f3(e2 | e1);
+    QCOMPARE(f3, 3);
+
+    QVERIFY(f3.testFlag(MyStrictEnum::StrictOne));
+    QVERIFY(!f1.testFlag(MyStrictEnum::StrictTwo));
+
+    QVERIFY(!f0);
+
+    QCOMPARE(f3 & int(1), 1);
+    QCOMPARE(f3 & uint(1), 1);
+    QCOMPARE(f3 & MyStrictEnum::StrictOne, 1);
+
+    MyStrictFlags aux;
+    aux = f3;
+    aux &= int(1);
+    QCOMPARE(aux, 1);
+
+    aux = f3;
+    aux &= uint(1);
+    QCOMPARE(aux, 1);
+
+    aux = f3;
+    aux &= MyStrictEnum::StrictOne;
+    QCOMPARE(aux, 1);
+
+    aux = f3;
+    aux &= f1;
+    QCOMPARE(aux, 1);
+
+    aux = f3 ^ f3;
+    QCOMPARE(aux, 0);
+
+    aux = f3 ^ f1;
+    QCOMPARE(aux, 2);
+
+    aux = f3 ^ f0;
+    QCOMPARE(aux, 3);
+
+    aux = f3 ^ MyStrictEnum::StrictOne;
+    QCOMPARE(aux, 2);
+
+    aux = f3 ^ MyStrictEnum::StrictZero;
+    QCOMPARE(aux, 3);
+
+    aux = f3;
+    aux ^= f3;
+    QCOMPARE(aux, 0);
+
+    aux = f3;
+    aux ^= f1;
+    QCOMPARE(aux, 2);
+
+    aux = f3;
+    aux ^= f0;
+    QCOMPARE(aux, 3);
+
+    aux = f3;
+    aux ^= MyStrictEnum::StrictOne;
+    QCOMPARE(aux, 2);
+
+    aux = f3;
+    aux ^= MyStrictEnum::StrictZero;
+    QCOMPARE(aux, 3);
+
+    aux = f1 | f2;
+    QCOMPARE(aux, 3);
+
+    aux = MyStrictEnum::StrictOne | MyStrictEnum::StrictTwo;
+    QCOMPARE(aux, 3);
+
+    aux = f1;
+    aux |= f2;
+    QCOMPARE(aux, 3);
+
+    aux = MyStrictEnum::StrictOne;
+    aux |= MyStrictEnum::StrictTwo;
+    QCOMPARE(aux, 3);
+
+    aux = ~f1;
+    QCOMPARE(aux, -2);
+
+    // Just to make sure it compiles
+    if (false)
+        qDebug() << f3;
+#endif
+}
+
 // (statically) check QTypeInfo for QFlags instantiations:
 enum MyEnum { Zero, One, Two, Four=4 };
 Q_DECLARE_FLAGS( MyFlags, MyEnum )