diff --git a/log-warper.cabal b/log-warper.cabal
--- a/log-warper.cabal
+++ b/log-warper.cabal
@@ -1,5 +1,5 @@
 name:                log-warper
-version:             1.0.1
+version:             1.0.2
 synopsis:            Flexible, configurable, monadic and pretty logging
 homepage:            https://github.com/serokell/log-warper
 license:             MIT
diff --git a/src/System/Wlog/CanLog.hs b/src/System/Wlog/CanLog.hs
--- a/src/System/Wlog/CanLog.hs
+++ b/src/System/Wlog/CanLog.hs
@@ -37,6 +37,7 @@
        , logMessage
        ) where
 
+import           Control.Concurrent         (modifyMVar_)
 import           Control.Monad.Base         (MonadBase)
 import           Control.Monad.Except       (ExceptT, MonadError)
 import qualified Control.Monad.RWS          as RWSLazy
@@ -44,6 +45,7 @@
 import qualified Control.Monad.State.Strict as StateStrict
 import           Control.Monad.Trans        (MonadTrans (lift))
 import           Control.Monad.Writer       (MonadWriter (tell), WriterT (runWriterT))
+
 import qualified Data.DList                 as DL (DList)
 import           Data.SafeCopy              (base, deriveSafeCopySimple)
 import           Data.Time                  (getCurrentTime)
diff --git a/src/System/Wlog/Formatter.hs b/src/System/Wlog/Formatter.hs
--- a/src/System/Wlog/Formatter.hs
+++ b/src/System/Wlog/Formatter.hs
@@ -30,6 +30,7 @@
        , varFormatter
        ) where
 
+import           Control.Concurrent     (myThreadId)
 import           Data.List              (span)
 import           Data.Monoid            (mconcat)
 import           Data.String            (IsString)
diff --git a/src/System/Wlog/Handler/Simple.hs b/src/System/Wlog/Handler/Simple.hs
--- a/src/System/Wlog/Handler/Simple.hs
+++ b/src/System/Wlog/Handler/Simple.hs
@@ -23,6 +23,7 @@
        , verboseStreamHandler
        ) where
 
+import           Control.Concurrent    (withMVar)
 import           Control.Exception     (SomeException)
 import           Data.Maybe            (fromMaybe)
 import qualified Data.Text.IO          as TIO
diff --git a/src/System/Wlog/Handler/Syslog.hs b/src/System/Wlog/Handler/Syslog.hs
--- a/src/System/Wlog/Handler/Syslog.hs
+++ b/src/System/Wlog/Handler/Syslog.hs
@@ -47,7 +47,7 @@
 
 import qualified Control.Exception         as E
 import           Control.Monad             (void, when)
-import           Data.Bits                 ()
+import           Data.Bits                 (shiftL, (.|.))
 import qualified Data.Text                 as T
 import qualified Data.Text.Encoding        as TE
 import           Network.BSD               (getHostByName, hostAddresses)
@@ -231,7 +231,7 @@
     do
     he <- getHostByName hostname
     s <- socket fam Datagram 0
-    let addr = SockAddrInet port (fromMaybe (panic "head in openlog_remote") $
+    let addr = SockAddrInet port (fromMaybe (error "head in openlog_remote") $
                                              head (hostAddresses he))
     openlog_generic s addr Datagram ident options fac pri
 
@@ -281,7 +281,7 @@
                     Datagram -> NBS.sendTo (logsocket sh) omsg' (address sh)
                     Stream   -> NBS.send   (logsocket sh) omsg'
                     sck        ->
-                        panic $ "sysloghandler: unsupported socket type " <> show sck <>
+                        error $ "sysloghandler: unsupported socket type " <> show sck <>
                                 " only datagram/stream sockets are supported"
           sendstr $ T.drop (fromIntegral sent) omsg
         toSyslogFormat m pidPart =
diff --git a/src/System/Wlog/Launcher.hs b/src/System/Wlog/Launcher.hs
--- a/src/System/Wlog/Launcher.hs
+++ b/src/System/Wlog/Launcher.hs
@@ -36,6 +36,7 @@
 import qualified Data.ByteString.Char8      as BS (putStrLn)
 import           Data.Yaml.Pretty           (defConfig, encodePretty)
 #endif
+import           Control.Concurrent         (modifyMVar_)
 import           Control.Error.Util         ((?:))
 import           Control.Exception          (throwIO)
 import qualified Data.HashMap.Strict        as HM hiding (HashMap)
diff --git a/src/System/Wlog/Logger.hs b/src/System/Wlog/Logger.hs
--- a/src/System/Wlog/Logger.hs
+++ b/src/System/Wlog/Logger.hs
@@ -49,6 +49,7 @@
        , updateGlobalLogger
        ) where
 
+import           Control.Concurrent.MVar    (modifyMVar, modifyMVar_)
 import           Data.List                  (isPrefixOf)
 import qualified Data.Map                   as Map
 import           Data.Maybe                 (fromJust)
@@ -217,7 +218,7 @@
     parentLoggers [] = return []
     parentLoggers name =
         let pname0 = (head . drop 1 . reverse . componentsOfName) name
-            pname = fromMaybe (panic "Logger.handle.parentLoggers: pname head failed") pname0
+            pname = fromMaybe (error "Logger.handle.parentLoggers: pname head failed") pname0
         in do parent <- getLogger pname
               next <- parentLoggers pname
               return (parent : next)
diff --git a/src/System/Wlog/Roller.hs b/src/System/Wlog/Roller.hs
--- a/src/System/Wlog/Roller.hs
+++ b/src/System/Wlog/Roller.hs
@@ -12,7 +12,7 @@
 
 import           Universum
 
-import           Control.Concurrent         (MVar, modifyMVar_, newMVar)
+import           Control.Concurrent         (modifyMVar_, withMVar)
 import           Formatting                 (sformat, shown, (%))
 import qualified Prelude                    (show)
 
@@ -45,7 +45,7 @@
     getLevel          = rhSeverity
     getFormatter      = rhFormatter
 
-    emit rh (_, msg) _      = rhWriteAction rh (panic "Handler is used internally") msg
+    emit rh (_, msg) _      = rhWriteAction rh (error "Handler is used internally") msg
     close RollerHandler{..} = withMVar rhFileHandle rhCloseAction
 
 data InvalidRotation = InvalidRotation !Text
diff --git a/src/System/Wlog/Wrapper.hs b/src/System/Wlog/Wrapper.hs
--- a/src/System/Wlog/Wrapper.hs
+++ b/src/System/Wlog/Wrapper.hs
@@ -21,9 +21,10 @@
        , setSeverityMaybe
        ) where
 
-import           Control.Concurrent.MVar    (MVar, newMVar, withMVar)
-import           System.IO                  (Handle, stderr, stdout)
 import           Universum
+
+import           Control.Concurrent.MVar    (withMVar)
+import           System.IO                  (Handle, stderr, stdout)
 
 import           System.Wlog.Formatter      (stderrFormatter, stdoutFormatter)
 import           System.Wlog.Handler        (LogHandler (setFormatter))