diff --git a/winpr/libwinpr/comm/comm.c b/winpr/libwinpr/comm/comm.c
index f891ca7d5..d3b909f2f 100644
--- a/winpr/libwinpr/comm/comm.c
+++ b/winpr/libwinpr/comm/comm.c
@@ -1378,19 +1378,6 @@ BOOL CommCloseHandle(HANDLE handle)
 	if (!CommIsHandled(handle))
 		return FALSE;
 
-	if (pComm->PendingEvents & SERIAL_EV_WINPR_WAITING)
-	{
-		ULONG WaitMask = 0;
-		DWORD BytesReturned = 0;
-
-		/* ensures to gracefully stop the WAIT_ON_MASK's loop */
-		if (!CommDeviceIoControl(handle, IOCTL_SERIAL_SET_WAIT_MASK, &WaitMask, sizeof(ULONG), NULL,
-		                         0, &BytesReturned, NULL))
-		{
-			CommLog_Print(WLOG_WARN, "failure to WAIT_ON_MASK's loop!");
-		}
-	}
-
 	DeleteCriticalSection(&pComm->ReadLock);
 	DeleteCriticalSection(&pComm->WriteLock);
 	DeleteCriticalSection(&pComm->EventsLock);
diff --git a/winpr/libwinpr/comm/comm_serial_sys.c b/winpr/libwinpr/comm/comm_serial_sys.c
index 8f4108001..e1125a0e3 100644
--- a/winpr/libwinpr/comm/comm_serial_sys.c
+++ b/winpr/libwinpr/comm/comm_serial_sys.c
@@ -1075,6 +1075,10 @@ static BOOL set_wait_mask(WINPR_COMM* pComm, const ULONG* pWaitMask)
 		/* waiting the end of the pending wait_on_mask() */
 		while (is_wait_set(pComm))
 			Sleep(10); /* 10ms */
+
+		EnterCriticalSection(&pComm->EventsLock);
+		pComm->PendingEvents &= ~SERIAL_EV_WINPR_STOP;
+		LeaveCriticalSection(&pComm->EventsLock);
 	}
 
 	/* NB: ensure to leave the critical section before to return */
@@ -1473,8 +1477,6 @@ static BOOL wait_on_mask(WINPR_COMM* pComm, ULONG* pOutputMask)
 
 		if (pComm->PendingEvents & SERIAL_EV_WINPR_STOP)
 		{
-			pComm->PendingEvents &= ~SERIAL_EV_WINPR_STOP;
-
 			/* pOutputMask must remain empty but should
 			 * not have been modified.
 			 *