diff --git a/cef.cabal b/cef.cabal
--- a/cef.cabal
+++ b/cef.cabal
@@ -1,5 +1,5 @@
 name:                cef
-version:             0.1.3
+version:             0.1.4
 synopsis:            CEF log format
 description:         This library is used to produce CEF log lines
 homepage:            http://github.com/picussecurity/haskell-cef.git
@@ -14,7 +14,7 @@
 library
   exposed-modules:  System.Log.CEF
   other-modules:    System.Log.CEF.Extensions
-  build-depends:    base >=4.7 && <4.9
+  build-depends:    base >=4.7 && <5
                   , text
                   , bytestring
                   , time
diff --git a/src/System/Log/CEF/Extensions.hs b/src/System/Log/CEF/Extensions.hs
--- a/src/System/Log/CEF/Extensions.hs
+++ b/src/System/Log/CEF/Extensions.hs
@@ -113,7 +113,6 @@
 
 --------------------------------------------------------------------------------
 import           Data.ByteString.Builder
-import           Data.Function           (on)
 import           Data.Monoid
 import qualified Data.Text               as T
 import qualified Data.Text.Encoding      as T