diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -12,7 +12,7 @@
 
 ## 2.4.4
 
-* New API: newFastLogger and ewTimedFastLogger.
+* New API: newFastLogger and newTimedFastLogger.
 * LogType and date cache are transferred from wai-logger.
 
 ## 2.4.3
diff --git a/System/Log/FastLogger.hs b/System/Log/FastLogger.hs
--- a/System/Log/FastLogger.hs
+++ b/System/Log/FastLogger.hs
@@ -1,5 +1,10 @@
 -- | This module provides a fast logging system which
 --   scales on multicore environments (i.e. +RTS -N\<x\>).
+--
+--   Note: This library does not guarantee correct ordering of log messages
+--   when program is run on more than one core thus users
+--   should rely more on message timestamps than on their order in the
+--   log.
 {-# LANGUAGE CPP #-}
 {-# LANGUAGE OverloadedStrings #-}
 
diff --git a/System/Log/FastLogger/FileIO.hs b/System/Log/FastLogger/FileIO.hs
--- a/System/Log/FastLogger/FileIO.hs
+++ b/System/Log/FastLogger/FileIO.hs
@@ -12,6 +12,11 @@
 import Data.Bits ((.|.))
 
 type FD = HANDLE
+#ifdef !MIN_VERSION_win32(2,3,1,0)
+-- This flag is not defined in System.Win32.File
+fILE_APPEND_DATA :: UINT
+fILE_APPEND_DATA = 0x0004
+#endif
 
 -- This flag is not defined in System.Win32.File
 fILE_APPEND_DATA :: UINT
diff --git a/System/Log/FastLogger/LogStr.hs b/System/Log/FastLogger/LogStr.hs
--- a/System/Log/FastLogger/LogStr.hs
+++ b/System/Log/FastLogger/LogStr.hs
@@ -24,6 +24,9 @@
 #if MIN_VERSION_base(4,5,0)
 import Data.Monoid ((<>))
 #endif
+#if MIN_VERSION_base(4,9,0)
+import Data.Semigroup (Semigroup)
+#endif
 import Data.String (IsString(..))
 import qualified Data.Text as T
 import qualified Data.Text.Encoding as T
@@ -51,6 +54,10 @@
 
 -- | Log message builder. Use ('<>') to append two LogStr in O(1).
 data LogStr = LogStr !Int Builder
+
+#if MIN_VERSION_base(4,9,0)
+instance Semigroup LogStr
+#endif
 
 instance Monoid LogStr where
     mempty = LogStr 0 (toBuilder BS.empty)
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:                2.4.7
+Version:                2.4.8
 Author:                 Kazu Yamamoto <kazu@iij.ad.jp>
 Maintainer:             Kazu Yamamoto <kazu@iij.ad.jp>
 License:                BSD3
@@ -27,10 +27,11 @@
                       , auto-update >= 0.1.2
                       , easy-file >= 0.2
                       , bytestring
-                      , bytestring-builder
                       , directory
                       , filepath
                       , text
+  if impl(ghc < 7.8)
+      Build-Depends:    bytestring-builder
   if os(windows)
       Cpp-Options:      -DWINDOWS
       Build-Depends:    time