diff --git a/src/Data/Validity/Text.hs b/src/Data/Validity/Text.hs
--- a/src/Data/Validity/Text.hs
+++ b/src/Data/Validity/Text.hs
@@ -1,4 +1,5 @@
-{-# OPTIONS_GHC -Wno-orphans #-}
+{-# OPTIONS_GHC -fno-warn-orphans #-}
+{-# LANGUAGE CPP #-}
 
 module Data.Validity.Text where
 
@@ -14,7 +15,9 @@
 import qualified Data.Text.Encoding.Error as E
 import Data.Text.Internal (Text(..))
 import qualified Data.Text.Unsafe as U
-
+#if !MIN_VERSION_base(4,8,0)
+import Data.Monoid (mconcat)
+#endif
 -- | A text is valid if the internal structure is consistent.
 instance Validity Text where
     isValid t@(Text arr off len) =
diff --git a/validity-text.cabal b/validity-text.cabal
--- a/validity-text.cabal
+++ b/validity-text.cabal
@@ -1,5 +1,5 @@
 name: validity-text
-version: 0.1.2.0
+version: 0.1.2.1
 cabal-version: >=1.10
 build-type: Simple
 license: MIT
@@ -21,7 +21,7 @@
     exposed-modules:
         Data.Validity.Text
     build-depends:
-        base <5,
+        base >= 4.7 && <5,
         validity -any,
         text -any,
         bytestring -any