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:             1.3.1
+version:             1.3.2
 synopsis:            Flexible, configurable, monadic and pretty logging
 homepage:            https://github.com/serokell/log-warper
 license:             MIT
@@ -61,7 +61,7 @@
                      , time                 >= 1.6.0.1
                      , transformers         >= 0.5.2
                      , transformers-base    >= 0.4.4
-                     , universum            >= 0.2
+                     , universum            >= 0.7
                      , unordered-containers >= 0.2.7.1
                      , yaml                 >= 0.8.20
   if !os(windows)
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
@@ -70,7 +70,7 @@
                                              readBack)
 import qualified System.Wlog.Handler        (handle)
 import           System.Wlog.Handler.Simple (streamHandler)
-import           System.Wlog.Severity       (LogRecord(..), Severity (..))
+import           System.Wlog.Severity       (LogRecord (..), Severity (..))
 
 
 ---------------------------------------------------------------------------
@@ -321,7 +321,7 @@
 removeAllHandlers :: IO ()
 removeAllHandlers =
     modifyMVar_ logInternalState $ \LogInternalState{..} -> do
-        let allHandlers = M.fold (\l r -> concat [r, view lHandlers l]) [] liTree
+        let allHandlers = M.foldr (\l r -> concat [r, view lHandlers l]) [] liTree
         mapM_ (\(HandlerT h) -> close h) allHandlers
         let newTree = map (lHandlers .~ []) liTree
         return $ LogInternalState newTree liPrefix
diff --git a/src/System/Wlog/LoggerConfig.hs b/src/System/Wlog/LoggerConfig.hs
--- a/src/System/Wlog/LoggerConfig.hs
+++ b/src/System/Wlog/LoggerConfig.hs
@@ -59,7 +59,6 @@
 import           Control.Monad.State    (put)
 import           Data.Aeson             (withObject)
 import qualified Data.HashMap.Strict    as HM hiding (HashMap)
-import           Data.List              (notElem)
 import           Data.Monoid            (Any (..))
 import           Data.Text              (Text)
 import qualified Data.Text.Buildable    as Buildable