diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,10 @@
 project adheres to the [Haskell Package Versioning
 Policy (PVP)](https://pvp.haskell.org)
 
+## [1.2.0.1] - 2018-10-06
+### Fixed
+  * Build fix for ghc-8.6
+
 ## [1.2.0.0] - 2018-04-03
 ### Changed
   * Internal debugging/RTS options handling has been changed. Compiling this package now implies that backends are also compiled in debug mode (no need to set the `-fdebug` cabal flag for those packages as well).
@@ -129,6 +133,7 @@
   * Initial release of the CUDA backend
 
 
+[1.2.0.1]:          https://github.com/AccelerateHS/accelerate/compare/v1.2.0.0...v1.2.0.1
 [1.2.0.0]:          https://github.com/AccelerateHS/accelerate/compare/v1.1.0.0...v1.2.0.0
 [1.1.1.0]:          https://github.com/AccelerateHS/accelerate/compare/v1.1.0.0...v1.1.1.0
 [1.1.0.0]:          https://github.com/AccelerateHS/accelerate/compare/1.0.0.0...v1.1.0.0
diff --git a/accelerate.cabal b/accelerate.cabal
--- a/accelerate.cabal
+++ b/accelerate.cabal
@@ -1,5 +1,5 @@
 Name:                   accelerate
-Version:                1.2.0.0
+Version:                1.2.0.1
 Cabal-version:          >= 1.18
 Tested-with:            GHC >= 7.8
 Build-type:             Custom
@@ -268,7 +268,7 @@
 
 Library
   Build-depends:
-          base                          >= 4.7 && < 4.12
+          base                          >= 4.7 && < 4.13
         , ansi-terminal                 >= 0.6.2
         , ansi-wl-pprint                >= 0.6
         , base-orphans                  >= 0.3
@@ -584,7 +584,7 @@
 
 source-repository this
   Type:                 git
-  Tag:                  v1.2.0.0
+  Tag:                  v1.2.0.1
   Location:             git://github.com/AccelerateHS/accelerate.git
 
 -- vim: nospell
diff --git a/src/Data/Array/Accelerate/Data/Monoid.hs b/src/Data/Array/Accelerate/Data/Monoid.hs
--- a/src/Data/Array/Accelerate/Data/Monoid.hs
+++ b/src/Data/Array/Accelerate/Data/Monoid.hs
@@ -6,6 +6,9 @@
 {-# LANGUAGE ScopedTypeVariables   #-}
 {-# LANGUAGE TypeFamilies          #-}
 {-# OPTIONS_GHC -fno-warn-orphans #-}
+#if __GLASGOW_HASKELL__ >= 806
+{-# LANGUAGE UndecidableInstances  #-}
+#endif
 -- |
 -- Module      : Data.Array.Accelerate.Data.Monoid
 -- Copyright   : [2016..2017] Trevor L. McDonell
diff --git a/src/Data/Array/Accelerate/Data/Semigroup.hs b/src/Data/Array/Accelerate/Data/Semigroup.hs
--- a/src/Data/Array/Accelerate/Data/Semigroup.hs
+++ b/src/Data/Array/Accelerate/Data/Semigroup.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE CPP                   #-}
 {-# LANGUAGE ConstraintKinds       #-}
 {-# LANGUAGE FlexibleContexts      #-}
 {-# LANGUAGE FlexibleInstances     #-}
@@ -7,6 +8,9 @@
 {-# LANGUAGE TypeFamilies          #-}
 {-# LANGUAGE ViewPatterns          #-}
 {-# OPTIONS_GHC -fno-warn-orphans #-}
+#if __GLASGOW_HASKELL__ >= 806
+{-# LANGUAGE UndecidableInstances  #-}
+#endif
 -- |
 -- Module      : Data.Array.Accelerate.Data.Semigroup
 -- Copyright   : [2018] Trevor L. McDonell
diff --git a/src/Data/Array/Accelerate/Lift.hs b/src/Data/Array/Accelerate/Lift.hs
--- a/src/Data/Array/Accelerate/Lift.hs
+++ b/src/Data/Array/Accelerate/Lift.hs
@@ -8,6 +8,9 @@
 {-# LANGUAGE OverlappingInstances  #-}
 {-# OPTIONS_GHC -fno-warn-unrecognised-pragmas #-}
 #endif
+#if __GLASGOW_HASKELL__ >= 806
+{-# LANGUAGE UndecidableInstances  #-}
+#endif
 -- |
 -- Module      : Data.Array.Accelerate.Lift
 -- Copyright   : [2016..2017] Manuel M T Chakravarty, Gabriele Keller, Trevor L. McDonell