diff --git a/System/Log/FastLogger/Date.hs b/System/Log/FastLogger/Date.hs
--- a/System/Log/FastLogger/Date.hs
+++ b/System/Log/FastLogger/Date.hs
@@ -23,7 +23,7 @@
 zonedDateCacheConf :: DateCacheConf UTCTime
 zonedDateCacheConf = DateCacheConf {
     getTime = getCurrentTime
-  , formatDate ut = do
+  , formatDate = \ut -> do
       zt <- utcToLocalZonedTime ut
       return $ BS.pack $ formatTime defaultTimeLocale "%d/%b/%Y:%T %z" zt
   }
diff --git a/fast-logger.cabal b/fast-logger.cabal
--- a/fast-logger.cabal
+++ b/fast-logger.cabal
@@ -1,5 +1,5 @@
 Name:                   fast-logger
-Version:                0.3.0
+Version:                0.3.1
 Author:                 Kazu Yamamoto <kazu@iij.ad.jp>
 Maintainer:             Kazu Yamamoto <kazu@iij.ad.jp>
 License:                BSD3