2 files changed, 8 insertions, 4 deletions

diff --git a/src/Network/Tox/AggregateSession.hs b/src/Network/Tox/AggregateSession.hs
index 513896cc..df16dc4e 100644
--- a/src/Network/Tox/AggregateSession.hs
+++ b/src/Network/Tox/AggregateSession.hs
@@ -155,9 +155,12 @@ keepAlive s q = do
 
     now <- getPOSIXTime
     join $ atomically $ do
-        Just ( k :-> tm ) <- PSQ.findMin <$> readTVar q
-        return $ if now < tm then threadDelay (toMicroseconds $ tm - now) >> again
-                             else doEvent again now (toEnum k)
+        PSQ.findMin <$> readTVar q >>= \case
+          Nothing           -> error "keepAlive: unexpected empty PSQ."
+          Just ( k :-> tm ) ->
+            return $ if now < tm then threadDelay (toMicroseconds $ tm - now) >> again
+                                 else doEvent again now (toEnum k)
+
 
 -- | This function forks two threads: the 'keepAlive' beacon-sending thread and
 -- a thread to read all packets from the provided 'Session' and forward them to
diff --git a/src/Network/Tox/NodeId.hs b/src/Network/Tox/NodeId.hs
index d5da692a..dc600db7 100644
--- a/src/Network/Tox/NodeId.hs
+++ b/src/Network/Tox/NodeId.hs
@@ -589,7 +589,8 @@ parseNoSpamJID jid = do
 
 solveBase64NoSpamID :: String -> PublicKey -> Either String NoSpamId
 solveBase64NoSpamID b64digits pub = do
-    NoSpam nospam (Just x) <- readEither $ '$' : map (\case; '?' -> '0'; c -> c) b64digits
+    NoSpam nospam mx <- readEither $ '$' : map (\case; '?' -> '0'; c -> c) b64digits
+    maybe (const $ Left "missing checksum") (flip ($)) mx $ \x -> do
     let nlo = fromIntegral (0x0FFFF .&. nospam) :: Word16
         nhi = fromIntegral (0x0FFFF .&. (nospam `shiftR` 16)) :: Word16
         sum = x `xor` nlo `xor` nhi `xor` xorsum pub