diff --git a/src/corelib/tools/qsharedpointer.cpp b/src/corelib/tools/qsharedpointer.cpp
index 5899cd9a548..ad8a3789084 100644
--- a/src/corelib/tools/qsharedpointer.cpp
+++ b/src/corelib/tools/qsharedpointer.cpp
@@ -1541,6 +1541,7 @@ QtSharedPointer::ExternalRefCountData *QtSharedPointer::ExternalRefCountData::ge
     ExternalRefCountData *x = ::new ExternalRefCountData(Qt::Uninitialized);
     x->strongref.storeRelaxed(-1);
     x->weakref.storeRelaxed(2);  // the QWeakPointer that called us plus the QObject itself
+    x->destroyer = nullptr;
 
     ExternalRefCountData *ret;
     if (d->sharedRefcount.testAndSetOrdered(nullptr, x, ret)) {     // ought to be release+acquire; this is acq_rel+acquire