diff --git a/src/System/ZMQ3/Base.hsc b/src/System/ZMQ3/Base.hsc
--- a/src/System/ZMQ3/Base.hsc
+++ b/src/System/ZMQ3/Base.hsc
@@ -229,7 +229,10 @@
 foreign import ccall unsafe "zmq.h zmq_socket_monitor"
     c_zmq_socket_monitor :: ZMQSocket -> CString -> CInt -> IO CInt
 
--- error messages
+-- errors
+
+foreign import ccall unsafe "zmq.h zmq_errno"
+    c_zmq_errno :: IO CInt
 
 foreign import ccall unsafe "zmq.h zmq_strerror"
     c_zmq_strerror :: CInt -> IO CString
diff --git a/src/System/ZMQ3/Error.hs b/src/System/ZMQ3/Error.hs
--- a/src/System/ZMQ3/Error.hs
+++ b/src/System/ZMQ3/Error.hs
@@ -1,4 +1,5 @@
 {-# LANGUAGE DeriveDataTypeable #-}
+
 -- We use our own functions for throwing exceptions in order to get
 -- the actual error message via 'zmq_strerror'. 0MQ defines additional
 -- error numbers besides those defined by the operating system, so
@@ -7,6 +8,7 @@
 module System.ZMQ3.Error where
 
 import Control.Monad
+import Control.Applicative
 import Control.Exception
 import Text.Printf
 import Data.Typeable (Typeable)
@@ -20,8 +22,8 @@
 
 -- | ZMQError encapsulates information about errors, which occur
 -- when using the native 0MQ API, such as error number and message.
-data ZMQError = ZMQError {
-    errno   :: Int     -- ^ Error number value.
+data ZMQError = ZMQError
+  { errno   :: Int     -- ^ Error number value.
   , source  :: String  -- ^ Source where this error originates from.
   , message :: String  -- ^ Actual error message.
   } deriving (Eq, Ord, Typeable)
@@ -34,7 +36,7 @@
 
 throwError :: String -> IO a
 throwError src = do
-    (Errno e) <- getErrno
+    (Errno e) <- zmqErrno
     msg       <- zmqErrnoMessage e
     throwIO $ ZMQError (fromIntegral e) src msg
 
@@ -49,7 +51,7 @@
 throwIfRetry :: (a -> Bool) -> String -> IO a -> IO a
 throwIfRetry p src act = do
     r <- act
-    if p r then getErrno >>= k else return r
+    if p r then zmqErrno >>= k else return r
   where
     k e | e == eINTR = throwIfRetry p src act
         | otherwise  = throwError src
@@ -75,7 +77,7 @@
 throwIfRetryMayBlock :: (a -> Bool) -> String -> IO a -> IO b -> IO a
 throwIfRetryMayBlock p src f on_block = do
     r <- f
-    if p r then getErrno >>= k else return r
+    if p r then zmqErrno >>= k else return r
   where
     k e | e == eINTR                      = throwIfRetryMayBlock p src f on_block
         | e == eWOULDBLOCK || e == eAGAIN = on_block >> throwIfRetryMayBlock p src f on_block
@@ -93,3 +95,5 @@
 zmqErrnoMessage :: CInt -> IO String
 zmqErrnoMessage e = c_zmq_strerror e >>= peekCString
 
+zmqErrno :: IO Errno
+zmqErrno = Errno <$> c_zmq_errno
diff --git a/tests/System/ZMQ3/Test/Properties.hs b/tests/System/ZMQ3/Test/Properties.hs
--- a/tests/System/ZMQ3/Test/Properties.hs
+++ b/tests/System/ZMQ3/Test/Properties.hs
@@ -1,6 +1,7 @@
 {-# LANGUAGE FlexibleInstances    #-}
 {-# LANGUAGE OverloadedStrings    #-}
 {-# OPTIONS_GHC -fno-warn-orphans #-}
+
 module System.ZMQ3.Test.Properties where
 
 import Test.QuickCheck
@@ -8,12 +9,12 @@
 import Test.Tools
 
 import Control.Applicative
+import Control.Concurrent.Async (wait)
 import Data.Int
 import Data.Word
 import Data.Restricted
 import Data.Maybe (fromJust)
 import Data.ByteString (ByteString)
-import Control.Concurrent
 import System.ZMQ3.Monadic
 import System.Posix.Types (Fd(..))
 import qualified Data.ByteString as SB
@@ -104,12 +105,11 @@
     msg' <- run $ runZMQ $ do
         sender   <- socket a
         receiver <- socket b
-        sync     <- liftIO newEmptyMVar
         bind receiver "inproc://endpoint"
-        async $ receive receiver >>= liftIO . putMVar sync
+        x <- async $ receive receiver
         connect sender "inproc://endpoint"
         send sender [] msg
-        liftIO $ takeMVar sync
+        liftIO $ wait x
     assert (msg == msg')
 
 prop_pub_sub :: (SocketType a, Subscriber b, SocketType b, Sender a, Receiver b) => a -> b -> ByteString -> Property
diff --git a/zeromq3-haskell.cabal b/zeromq3-haskell.cabal
--- a/zeromq3-haskell.cabal
+++ b/zeromq3-haskell.cabal
@@ -1,5 +1,5 @@
 name:               zeromq3-haskell
-version:            0.5
+version:            0.5.1
 synopsis:           Bindings to ZeroMQ 3.x
 category:           System, FFI
 license:            MIT
@@ -59,6 +59,7 @@
     other-modules:    Test.Tools
     build-depends:    zeromq3-haskell
                     , base >= 3 && < 5
+                    , async
                     , containers
                     , bytestring
                     , transformers