diff --git a/os/connection.c b/os/connection.c
index 3223eeb5d..8a28df68e 100644
--- a/os/connection.c
+++ b/os/connection.c
@@ -281,6 +281,7 @@ CreateWellKnownSockets(void)
         int fd = _XSERVTransGetConnectionNumber(ListenTransConns[i]);
 
         ListenTransFds[i] = fd;
+        _XSERVTransSetOption(ListenTransConns[i], TRANS_CLOSEONEXEC, 0);
         SetNotifyFd(fd, EstablishNewConnections, X_NOTIFY_READ, NULL);
 
         if (!_XSERVTransIsLocal(ListenTransConns[i]))