diff --git a/serokell-util.cabal b/serokell-util.cabal
--- a/serokell-util.cabal
+++ b/serokell-util.cabal
@@ -1,5 +1,5 @@
 name:                serokell-util
-version:             0.4.1
+version:             0.5.0
 synopsis:            General-purpose functions by Serokell
 homepage:            https://github.com/serokell/serokell-util
 license:             MIT
diff --git a/src/Serokell/Util/Concurrent.hs b/src/Serokell/Util/Concurrent.hs
--- a/src/Serokell/Util/Concurrent.hs
+++ b/src/Serokell/Util/Concurrent.hs
@@ -5,13 +5,10 @@
        , modifyTVarS
        ) where
 
-import qualified Control.Concurrent          as Concurrent
-import           Control.Concurrent.STM      (STM)
-import           Control.Concurrent.STM.TVar (TVar, readTVar, writeTVar)
-import           Control.Monad.State         (StateT, runStateT)
-import           Control.Monad.Trans         (MonadIO (liftIO))
-import           Data.Time.Units             (TimeUnit (toMicroseconds))
+import           Universum
 
+import qualified Control.Concurrent as Concurrent
+import           Data.Time.Units    (TimeUnit (toMicroseconds))
 
 -- | Convenient version of Control.Concurrent.threadDelay which takes
 -- any time-unit and operates in any MonadIO