Index: /trunk/src/VBox/Runtime/r3/tcp.cpp
===================================================================
--- /trunk/src/VBox/Runtime/r3/tcp.cpp	(revision 27498)
+++ /trunk/src/VBox/Runtime/r3/tcp.cpp	(revision 27499)
@@ -1012,5 +1012,6 @@
     switch (sizeof(RTSOCKET))
     {
-        case 4: return (RTSOCKET)ASMAtomicXchgS32((int32_t volatile *)pSock, (int32_t)Sock);
+        case 4: return (RTSOCKET)ASMAtomicXchgS32((int32_t volatile *)pSock, (int32_t)(uintptr_t)Sock);
+        case 8: return (RTSOCKET)ASMAtomicXchgS64((int64_t volatile *)pSock, (int64_t)(uintptr_t)Sock);
         default:
             AssertReleaseFailed();