@@ -234,7 +234,7 @@ control FrameWindowUpdate header bs Context{connectionWindow} = do
234234 WindowUpdateFrame n <- guardIt $ decodeWindowUpdateFrame header bs
235235 !w <- atomically $ do
236236 w0 <- readTVar connectionWindow
237− let w1 = w0 + n
237+ let !w1 = w0 + n
238238 writeTVar connectionWindow w1
239239 return w1
240240 when (isWindowOverflow w) $ E.throwIO $ ConnectionError FlowControlError "control window should be less than 2^31"
@@ -341,7 +341,7 @@ stream FrameWindowUpdate header@FrameHeader{streamId} bs _ s Stream{streamWindow
341341 WindowUpdateFrame n <- guardIt $ decodeWindowUpdateFrame header bs
342342 !w <- atomically $ do
343343 w0 <- readTVar streamWindow
344− let w1 = w0 + n
344+ let !w1 = w0 + n
345345 writeTVar streamWindow w1
346346 return w1
347347 when (isWindowOverflow w) $