diff --git a/drivers/staging/vt6656/card.c b/drivers/staging/vt6656/card.c
index bb91ffadbf5dfea466cecc69902a446321eb2a35..ce7ee45d3086dfa100be3030ae3579f8ba5a8c06 100644
--- a/drivers/staging/vt6656/card.c
+++ b/drivers/staging/vt6656/card.c
@@ -727,7 +727,7 @@ u64 CARDqGetNextTBTT(u64 qwTSF, u16 wBeaconInterval)
 
     uBeaconInterval = wBeaconInterval * 1024;
     // Next TBTT = ((local_current_TSF / beacon_interval) + 1 ) * beacon_interval
-	uLowNextTBTT = ((qwTSF & 0xffffffffU) >> 10) << 10;
+	uLowNextTBTT = ((qwTSF & 0xffffffffULL) >> 10) << 10;
 	uLowRemain = (uLowNextTBTT) % uBeaconInterval;
 	uHighRemain = ((0x80000000 % uBeaconInterval) * 2 * (u32)(qwTSF >> 32))
 		% uBeaconInterval;