diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,5 +1,10 @@
 # Revision history for staversion
 
+## 0.2.1.2  -- 2017-07-29
+
+* Fix build and test with `megaparsec-4`.
+
+
 ## 0.2.1.1  -- 2017-07-29
 
 * Support `megaparsec-6.0`, with compatibility wrapper "Staversion.Internal.Megaparsec".
diff --git a/src/Staversion/Internal/Megaparsec.hs b/src/Staversion/Internal/Megaparsec.hs
--- a/src/Staversion/Internal/Megaparsec.hs
+++ b/src/Staversion/Internal/Megaparsec.hs
@@ -17,9 +17,10 @@
        ) where
 
 import Text.Megaparsec
+import Data.Text (Text)
 
 #if MIN_VERSION_megaparsec(6,0,0)
-import Data.Text (Text, pack, unpack)
+import Data.Text (pack, unpack)
 import Data.Void (Void)
 import Text.Megaparsec.Char hiding (string, string')
 import qualified Text.Megaparsec.Char as MC
@@ -40,12 +41,15 @@
 string' :: String -> Parser String
 string' = liftToString MC.string'
 
-#else
-
-import Data.Text (Text)
+#elif MIN_VERSION_megaparsec(5,0,0)
 
 -- | From "Text.Megaparsec.Text".
 type Parser = Parsec Dec Text
+
+#else
+
+-- | From "Text.Megaparsec.Text"
+type Parser = Parsec Text
 
 #endif
 
diff --git a/staversion.cabal b/staversion.cabal
--- a/staversion.cabal
+++ b/staversion.cabal
@@ -1,5 +1,5 @@
 name:                   staversion
-version:                0.2.1.1
+version:                0.2.1.2
 author:                 Toshio Ito <debug.ito@gmail.com>
 maintainer:             Toshio Ito <debug.ito@gmail.com>
 license:                BSD3