diff --git a/src/HistoryProviderServer.hs b/src/HistoryProviderServer.hs
index f35209b..ae625be 100644
--- a/src/HistoryProviderServer.hs
+++ b/src/HistoryProviderServer.hs
@@ -19,7 +19,7 @@ import           ATrade.Types               (Bar (..), BarTimeframe (..),
                                              TickerId, toDouble)
 import           Colog                      (HasLog (getLogAction, setLogAction),
                                              LogAction (LogAction, unLogAction))
-import           Control.Concurrent         (ThreadId, forkIO)
+import           Control.Concurrent         (ThreadId)
 import           Control.Concurrent.STM     (TVar, atomically, newTVarIO,
                                              readTVarIO, writeTVar)
 import           Control.Exception          (bracket)
@@ -45,6 +45,7 @@ import           Data.Time.Clock            (diffUTCTime, getCurrentTime,
                                              secondsToDiffTime)
 import           Data.Time.Clock.POSIX      (utcTimeToPOSIXSeconds)
 import           Prelude                    hiding (log)
+import           SlaveThread                (fork)
 import           System.ZMQ4                (Context, Router (Router), bind,
                                              close, receiveMulti, sendMulti,
                                              socket)
@@ -182,7 +183,7 @@ startHistoryProviderServer ctx endpoint txmlH tisH logger = do
         , eTxml = txmlH
         , eTisHandle = tisH
     }
-  hpsThreadId <- liftIO . forkIO $ (runReaderT . unApp) workThread env
+  hpsThreadId <- liftIO . fork $ (runReaderT . unApp) workThread env
   pure HistoryProviderServerHandle {..}
 
 stopHistoryProviderServer ::
diff --git a/src/TXMLConnector.hs b/src/TXMLConnector.hs
index 4576d46..e918f83 100644
--- a/src/TXMLConnector.hs
+++ b/src/TXMLConnector.hs
@@ -22,7 +22,7 @@ import           ATrade.Types                   (Order, OrderId)
 import           Colog                          (HasLog (getLogAction, setLogAction),
                                                  LogAction (LogAction, unLogAction))
 import           Config                         (TransaqConnectorConfig (..))
-import           Control.Concurrent             (ThreadId, forkIO)
+import           Control.Concurrent             (ThreadId)
 import           Control.Concurrent.BoundedChan (BoundedChan)
 import           Control.Concurrent.STM         (TVar, atomically,
                                                  newEmptyTMVar, newEmptyTMVarIO,
@@ -40,6 +40,7 @@ import qualified Data.Text                      as T
 import           Data.Time.Clock                (UTCTime, getCurrentTime)
 import           GHC.Exts                       (IsList (..))
 import           Prelude                        hiding (log)
+import           SlaveThread                    (fork)
 import           TickerInfoServer               (TickerInfoServerHandle)
 import           TickTable                      (newTickTable)
 import           Transaq                        (TransaqResponse)
@@ -143,7 +144,7 @@ start logger' config' qssChannel' tisH = do
         , runVar = runVar'
         , timerVar = timerVar'
         }
-  workThreadId <- forkIO $ (runReaderT . unApp) workThread env
+  workThreadId <- fork $ (runReaderT . unApp) workThread env
   return $ TXMLConnectorHandle
     { threadId = workThreadId
     , notificationQueue = notificationQueue'
diff --git a/src/TXMLConnector/Internal.hs b/src/TXMLConnector/Internal.hs
index 8dc59c7..878bb49 100644
--- a/src/TXMLConnector/Internal.hs
+++ b/src/TXMLConnector/Internal.hs
@@ -22,7 +22,7 @@ import           Config                         (SubscriptionConfig (Subscriptio
                                                  transaqHost, transaqLogLevel,
                                                  transaqLogPath, transaqLogin,
                                                  transaqPassword, transaqPort)
-import           Control.Concurrent             (forkIO, threadDelay)
+import           Control.Concurrent             (threadDelay)
 import           Control.Concurrent.STM         (TVar, atomically, modifyTVar',
                                                  orElse, putTMVar, readTMVar,
                                                  readTVar, readTVarIO,
@@ -36,6 +36,7 @@ import qualified Data.Bimap                     as BM
 import           Data.Maybe                     (mapMaybe)
 import qualified Data.Text                      as T
 import qualified Deque.Strict                   as D
+import           SlaveThread                    (fork)
 import           Text.XML.Light.Input           (parseXML)
 import           Text.XML.Light.Types           (Content (Elem),
                                                  Element (elName),
@@ -204,7 +205,7 @@ workThread = do
         Just cb -> do
           serverConnectionState <- asks serverConnected
           timerVar' <- asks timerVar
-          void $ liftIO $ forkIO $ whileM $ do
+          void $ liftIO $ fork $ whileM $ do
             threadDelay 5000000
             void . liftIO . atomically $ tryPutTMVar timerVar' ()
             connStatus <- liftIO . readTVarIO $ serverConnectionState
@@ -427,7 +428,7 @@ handleConnected = do
             Left result -> do
               case headMay (parseXML result) >>= parseContent of
                 Just (TransaqResponseResult (ResponseSuccess (Just transactionId))) -> do
-                  State <- asks brokerState
+                  brState <- asks brokerState
                   respVar <- asks responseVar
                   liftIO $ atomically $ do
                     modifyTVar' (bsOrderMap brState) (M.insert (orderId order) order)
@@ -475,7 +476,9 @@ handleConnected = do
     requestTimeoutValue = 10
 
     sendCancelOrder transactionId' = do
-      v <- sendCommand . toXml $ (CommandCancelOrder $ toInteger transactionId)
+      respVar <- asks responseVar
+      resp <- liftIO . atomically $ readTMVar respVar
+      v <- sendCommand . toXml $ (CommandCancelOrder $ toInteger transactionId')
       case v of
         Left result -> do
           log Debug "TXMLConnector.WorkThread" $ "Cancellation result: " <> (T.pack . show) result
diff --git a/src/TickerInfoServer.hs b/src/TickerInfoServer.hs
index 8b36745..250dc62 100644
--- a/src/TickerInfoServer.hs
+++ b/src/TickerInfoServer.hs
@@ -16,7 +16,7 @@ import           ATrade.Logging              (Message,
                                               logWith)
 import           ATrade.Types                (Tick, TickerId, security)
 import           Colog                       (LogAction)
-import           Control.Concurrent          (ThreadId, forkIO)
+import           Control.Concurrent          (ThreadId)
 import           Control.Concurrent.STM      (TVar, atomically, newTVarIO,
                                               readTVarIO)
 import           Control.Concurrent.STM.TVar (modifyTVar', writeTVar)
@@ -34,6 +34,7 @@ import qualified Data.Text                   as T
 import           Data.Text.Encoding          (decodeUtf8With, encodeUtf8)
 import           Data.Text.Encoding.Error    (replace)
 import           Prelude                     hiding (log)
+import           SlaveThread                 (fork)
 import           System.ZMQ4                 (Context, Router (Router), bind,
                                               connect, receiveMulti, sendMulti,
                                               withSocket)
@@ -87,7 +88,7 @@ startTickerInfoServer :: LogAction IO Message -> Context -> T.Text -> IO TickerI
 startTickerInfoServer logger ctx endpoint = do
   tisRun <- newTVarIO True
   tisMap <- newTVarIO M.empty
-  tisThreadId <- forkIO $ tisThread tisRun tisMap
+  tisThreadId <- fork $ tisThread tisRun tisMap
   pure $ TickerInfoServerHandle {..}
   where
     log = logWith logger
diff --git a/transaq-connector.cabal b/transaq-connector.cabal
index ae12556..e3a5247 100644
--- a/transaq-connector.cabal
+++ b/transaq-connector.cabal
@@ -120,6 +120,7 @@ test-suite transaq-connector-test
                      , network-uri
                      , ekg-statsd
                      , ekg-core
+                     , slave-thread
   default-extensions:  OverloadedStrings
                      , MultiWayIf
                      , MultiParamTypeClasses