diff --git a/src/corelib/plugin/quuid.h b/src/corelib/plugin/quuid.h
index 3142062665..0cead3a8b7 100644
--- a/src/corelib/plugin/quuid.h
+++ b/src/corelib/plugin/quuid.h
@@ -70,7 +70,7 @@ public:
         }
     };
 
-    constexpr QUuid() noexcept {}
+    constexpr QUuid() noexcept : data1(0), data2(0), data3(0), data4{0,0,0,0,0,0,0,0} {}
 
     constexpr QUuid(uint l, ushort w1, ushort w2, uchar b1, uchar b2, uchar b3,
                            uchar b4, uchar b5, uchar b6, uchar b7, uchar b8) noexcept
@@ -183,10 +183,10 @@ public:
     NSUUID *toNSUUID() const Q_DECL_NS_RETURNS_AUTORELEASED;
 #endif
 
-    uint    data1 = 0;
-    ushort  data2 = 0;
-    ushort  data3 = 0;
-    uchar   data4[8] = {};
+    uint    data1;
+    ushort  data2;
+    ushort  data3;
+    uchar   data4[8];
 
 private:
     static constexpr Id128Bytes bswap(Id128Bytes b)
@@ -244,6 +244,7 @@ inline QUuid QUuid::fromBytes(const void *bytes, QSysInfo::Endian order) noexcep
 
 #ifdef __SIZEOF_INT128__
 constexpr inline QUuid::QUuid(quint128 uuid, QSysInfo::Endian order) noexcept
+    : QUuid()
 {
     if (order == QSysInfo::LittleEndian)
         uuid = qbswap(uuid);