diff --git a/benchmark/Main.hs b/benchmark/Main.hs
index ee1fba7..9df5ec5 100644
--- a/benchmark/Main.hs
+++ b/benchmark/Main.hs
@@ -25,11 +25,10 @@ data Program = Program
   }
 
 parseBS :: ByteString -> IO BFProgram
-parseBS =
-  either (throwIO . userError . show) pure
-    . parseBF
-    . unpack
-    . decodeUtf8With lenientDecode
+parseBS = throwIfLeft . parseBF . unpack . decodeUtf8With lenientDecode
+  where
+    throwIfLeft (Left e) = throwIO . userError . show $ e
+    throwIfLeft (Right v) = pure v
 
 brainfuckFiles :: [(FilePath, ByteString)]
 brainfuckFiles = filter isBrainfuckFile files
diff --git a/src/Language/BrainHask/Optimizer.hs b/src/Language/BrainHask/Optimizer.hs
index 468f7b1..318bf78 100644
--- a/src/Language/BrainHask/Optimizer.hs
+++ b/src/Language/BrainHask/Optimizer.hs
@@ -1,6 +1,5 @@
 {-# LANGUAGE DataKinds #-}
 {-# LANGUAGE DeriveGeneric #-}
-{-# LANGUAGE OverloadedStrings #-}
 
 module Language.BrainHask.Optimizer (optimize, OptimizationLevel (..)) where
 
diff --git a/src/Language/BrainHask/Preprocessor.hs b/src/Language/BrainHask/Preprocessor.hs
index 4255f08..dd93657 100644
--- a/src/Language/BrainHask/Preprocessor.hs
+++ b/src/Language/BrainHask/Preprocessor.hs
@@ -1,8 +1,8 @@
 module Language.BrainHask.Preprocessor (preprocess) where
 
+import Data.Functor (($>))
 import Data.Transformer
 import Language.BrainHask.Types
-import Data.Functor (($>))
 
 type Preprocessor a = Transformer BFOp (ILOp Int a)