diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+## [v1.4.2.2](https://github.com/diagrams/diagrams-lib/tree/v1.4.2.2) (2018-05-08)
+
+- Fixes for GHC < 8.0
+
 ## [v1.4.2.1](https://github.com/diagrams/diagrams-lib/tree/v1.4.2.1) (2018-04-13)
 
 - Allow `base-4.11` (GHC 8.4)
diff --git a/diagrams-lib.cabal b/diagrams-lib.cabal
--- a/diagrams-lib.cabal
+++ b/diagrams-lib.cabal
@@ -1,5 +1,5 @@
 Name:                diagrams-lib
-Version:             1.4.2.1
+Version:             1.4.2.2
 Synopsis:            Embedded domain-specific language for declarative graphics
 Description:         Diagrams is a flexible, extensible EDSL for creating
                      graphics of many types.  Graphics can be created
@@ -21,7 +21,7 @@
 Cabal-version:       1.18
 Extra-source-files:  CHANGELOG.md, README.markdown, diagrams/*.svg
 Extra-doc-files:     diagrams/*.svg
-Tested-with:         GHC == 7.8.4, GHC == 7.10.2, GHC == 8.0.1, GHC == 8.2.2, GHC == 8.4.1
+Tested-with:         GHC == 7.8.4, GHC == 7.10.3, GHC == 8.0.2, GHC == 8.2.2, GHC == 8.4.2
 Source-repository head
   type:     git
   location: http://github.com/diagrams/diagrams-lib.git
diff --git a/src/Diagrams/Align.hs b/src/Diagrams/Align.hs
--- a/src/Diagrams/Align.hs
+++ b/src/Diagrams/Align.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE ConstraintKinds #-}
 {-# LANGUAGE ConstrainedClassMethods     #-}
 {-# LANGUAGE FlexibleContexts     #-}
 {-# LANGUAGE TypeFamilies         #-}
diff --git a/src/Diagrams/Angle.hs b/src/Diagrams/Angle.hs
--- a/src/Diagrams/Angle.hs
+++ b/src/Diagrams/Angle.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE ConstraintKinds            #-}
 {-# LANGUAGE DeriveFunctor              #-}
 {-# LANGUAGE FlexibleContexts           #-}
 {-# LANGUAGE FlexibleInstances          #-}
diff --git a/src/Diagrams/Animation.hs b/src/Diagrams/Animation.hs
--- a/src/Diagrams/Animation.hs
+++ b/src/Diagrams/Animation.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE ConstraintKinds #-}
 {-# LANGUAGE CPP                   #-}
 {-# LANGUAGE FlexibleContexts      #-}
 {-# LANGUAGE MultiParamTypeClasses #-}
diff --git a/src/Diagrams/Attributes.hs b/src/Diagrams/Attributes.hs
--- a/src/Diagrams/Attributes.hs
+++ b/src/Diagrams/Attributes.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE ConstraintKinds #-}
 {-# LANGUAGE CPP                        #-}
 {-# LANGUAGE DeriveDataTypeable         #-}
 {-# LANGUAGE DeriveFunctor              #-}
diff --git a/src/Diagrams/BoundingBox.hs b/src/Diagrams/BoundingBox.hs
--- a/src/Diagrams/BoundingBox.hs
+++ b/src/Diagrams/BoundingBox.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE ConstraintKinds #-}
 {-# LANGUAGE DeriveFunctor              #-}
 {-# LANGUAGE FlexibleContexts           #-}
 {-# LANGUAGE FlexibleInstances          #-}
diff --git a/src/Diagrams/Combinators.hs b/src/Diagrams/Combinators.hs
--- a/src/Diagrams/Combinators.hs
+++ b/src/Diagrams/Combinators.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE ConstraintKinds #-}
 {-# LANGUAGE FlexibleContexts      #-}
 {-# LANGUAGE MultiParamTypeClasses #-}
 {-# LANGUAGE Rank2Types            #-}
diff --git a/src/Diagrams/CubicSpline.hs b/src/Diagrams/CubicSpline.hs
--- a/src/Diagrams/CubicSpline.hs
+++ b/src/Diagrams/CubicSpline.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE ConstraintKinds #-}
 {-# LANGUAGE FlexibleContexts #-}
 {-# LANGUAGE TypeFamilies     #-}
 {-# OPTIONS_GHC -fno-warn-incomplete-patterns #-}
diff --git a/src/Diagrams/Deform.hs b/src/Diagrams/Deform.hs
--- a/src/Diagrams/Deform.hs
+++ b/src/Diagrams/Deform.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE ConstraintKinds #-}
 {-# LANGUAGE FlexibleContexts      #-}
 {-# LANGUAGE FlexibleInstances     #-}
 {-# LANGUAGE MultiParamTypeClasses #-}
diff --git a/src/Diagrams/LinearMap.hs b/src/Diagrams/LinearMap.hs
--- a/src/Diagrams/LinearMap.hs
+++ b/src/Diagrams/LinearMap.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE ConstraintKinds #-}
 {-# LANGUAGE ConstraintKinds       #-}
 {-# LANGUAGE FlexibleContexts      #-}
 {-# LANGUAGE FlexibleInstances     #-}
diff --git a/src/Diagrams/Located.hs b/src/Diagrams/Located.hs
--- a/src/Diagrams/Located.hs
+++ b/src/Diagrams/Located.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE ConstraintKinds #-}
 {-# LANGUAGE CPP                   #-}
 {-# LANGUAGE FlexibleContexts      #-}
 {-# LANGUAGE MultiParamTypeClasses #-}
diff --git a/src/Diagrams/Names.hs b/src/Diagrams/Names.hs
--- a/src/Diagrams/Names.hs
+++ b/src/Diagrams/Names.hs
@@ -1,5 +1,10 @@
+{-# LANGUAGE ConstraintKinds #-}
 {-# LANGUAGE FlexibleContexts #-}
 {-# LANGUAGE MonoLocalBinds   #-}
+
+{-# OPTIONS_GHC -fno-warn-unused-imports #-}
+  -- for Data.Semigroup
+
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Diagrams.Names
diff --git a/src/Diagrams/Path.hs b/src/Diagrams/Path.hs
--- a/src/Diagrams/Path.hs
+++ b/src/Diagrams/Path.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE ConstraintKinds #-}
 {-# LANGUAGE CPP                        #-}
 #if __GLASGOW_HASKELL__ >= 707
 {-# LANGUAGE DeriveDataTypeable         #-}
@@ -12,6 +13,10 @@
 {-# LANGUAGE UndecidableInstances       #-}
 {-# LANGUAGE ViewPatterns               #-}
 {-# LANGUAGE DeriveGeneric              #-}
+
+{-# OPTIONS_GHC -fno-warn-unused-imports #-}
+  -- for Data.Semigroup
+
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Diagrams.Path
diff --git a/src/Diagrams/Segment.hs b/src/Diagrams/Segment.hs
--- a/src/Diagrams/Segment.hs
+++ b/src/Diagrams/Segment.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE ConstraintKinds #-}
 {-# LANGUAGE BangPatterns               #-}
 {-# LANGUAGE DeriveFunctor              #-}
 {-# LANGUAGE EmptyDataDecls             #-}
diff --git a/src/Diagrams/Size.hs b/src/Diagrams/Size.hs
--- a/src/Diagrams/Size.hs
+++ b/src/Diagrams/Size.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE ConstraintKinds #-}
 {-# LANGUAGE CPP                        #-}
 #if __GLASGOW_HASKELL__ >= 707
 {-# LANGUAGE DeriveDataTypeable         #-}
diff --git a/src/Diagrams/Tangent.hs b/src/Diagrams/Tangent.hs
--- a/src/Diagrams/Tangent.hs
+++ b/src/Diagrams/Tangent.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE ConstraintKinds #-}
 {-# LANGUAGE GADTs                #-} -- for ghc < 7.8, TypeFamilies covers GADT patten mathcing in > 7.8
 {-# LANGUAGE FlexibleContexts     #-}
 {-# LANGUAGE FlexibleInstances    #-}
diff --git a/src/Diagrams/ThreeD/Align.hs b/src/Diagrams/ThreeD/Align.hs
--- a/src/Diagrams/ThreeD/Align.hs
+++ b/src/Diagrams/ThreeD/Align.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE ConstraintKinds #-}
 {-# LANGUAGE TypeFamilies    #-}
 
 -----------------------------------------------------------------------------
diff --git a/src/Diagrams/ThreeD/Light.hs b/src/Diagrams/ThreeD/Light.hs
--- a/src/Diagrams/ThreeD/Light.hs
+++ b/src/Diagrams/ThreeD/Light.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE ConstraintKinds #-}
 {-# LANGUAGE DeriveDataTypeable    #-}
 {-# LANGUAGE FlexibleContexts      #-}
 {-# LANGUAGE MultiParamTypeClasses #-}
diff --git a/src/Diagrams/ThreeD/Shapes.hs b/src/Diagrams/ThreeD/Shapes.hs
--- a/src/Diagrams/ThreeD/Shapes.hs
+++ b/src/Diagrams/ThreeD/Shapes.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE ConstraintKinds #-}
 {-# LANGUAGE CPP                   #-}
 {-# LANGUAGE DeriveDataTypeable    #-}
 {-# LANGUAGE FlexibleContexts      #-}
diff --git a/src/Diagrams/ThreeD/Size.hs b/src/Diagrams/ThreeD/Size.hs
--- a/src/Diagrams/ThreeD/Size.hs
+++ b/src/Diagrams/ThreeD/Size.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE ConstraintKinds #-}
 {-# LANGUAGE FlexibleContexts #-}
 {-# LANGUAGE TypeFamilies     #-}
 
diff --git a/src/Diagrams/ThreeD/Transform.hs b/src/Diagrams/ThreeD/Transform.hs
--- a/src/Diagrams/ThreeD/Transform.hs
+++ b/src/Diagrams/ThreeD/Transform.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE ConstraintKinds #-}
 {-# LANGUAGE FlexibleContexts      #-}
 {-# LANGUAGE FlexibleInstances     #-}
 {-# LANGUAGE MultiParamTypeClasses #-}
@@ -5,6 +6,10 @@
 {-# LANGUAGE TypeFamilies          #-}
 {-# LANGUAGE TypeOperators         #-}
 {-# LANGUAGE ViewPatterns          #-}
+
+{-# OPTIONS_GHC -fno-warn-unused-imports #-}
+  -- for Data.Semigroup
+
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Diagrams.ThreeD.Transform
diff --git a/src/Diagrams/Trace.hs b/src/Diagrams/Trace.hs
--- a/src/Diagrams/Trace.hs
+++ b/src/Diagrams/Trace.hs
@@ -1,5 +1,10 @@
+{-# LANGUAGE ConstraintKinds #-}
 {-# LANGUAGE FlexibleContexts #-}
 {-# LANGUAGE MonoLocalBinds   #-}
+
+{-# OPTIONS_GHC -fno-warn-unused-imports #-}
+  -- for Data.Semigroup
+
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Diagrams.Trace
diff --git a/src/Diagrams/Trail.hs b/src/Diagrams/Trail.hs
--- a/src/Diagrams/Trail.hs
+++ b/src/Diagrams/Trail.hs
@@ -1,3 +1,5 @@
+{-# LANGUAGE ConstraintKinds #-}
+{-# LANGUAGE CPP                        #-}
 {-# LANGUAGE EmptyDataDecls             #-}
 {-# LANGUAGE FlexibleContexts           #-}
 {-# LANGUAGE FlexibleInstances          #-}
@@ -174,7 +176,19 @@
 --   beginning which have a combined arc length of at least 5).
 
 newtype SegTree v n = SegTree (FingerTree (SegMeasure v n) (Segment Closed v n))
-  deriving (Eq, Ord, Show, Monoid, Semigroup, Transformable, FT.Measured (SegMeasure v n))
+  deriving (Eq, Ord, Show, Monoid, Transformable, FT.Measured (SegMeasure v n))
+
+-- Only derive the Semigroup instance for versions of base that
+-- include Semigroup.  This is because the fingertree package has
+-- similar CPP to only export a Semigroup instance for those versions
+-- of base, so for GHC 7.10 and earlier we get a 'no instance found'
+-- error when trying to derive the Semigroup instance for SegTree.  It
+-- would also be possible to depend on the 'semigroups' package in
+-- order to get the Semigroup class regardless of base version, but
+-- presumably fingertree didn't want to add a dependency.
+#if MIN_VERSION_base(4,9,0)
+deriving instance (Ord n, Floating n, Metric v) => Semigroup (SegTree v n)
+#endif
 
 instance Wrapped (SegTree v n) where
   type Unwrapped (SegTree v n) = FingerTree (SegMeasure v n) (Segment Closed v n)
diff --git a/src/Diagrams/TrailLike.hs b/src/Diagrams/TrailLike.hs
--- a/src/Diagrams/TrailLike.hs
+++ b/src/Diagrams/TrailLike.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE ConstraintKinds #-}
 {-# LANGUAGE FlexibleContexts     #-}
 {-# LANGUAGE FlexibleInstances    #-}
 {-# LANGUAGE TypeFamilies         #-}
diff --git a/src/Diagrams/Transform.hs b/src/Diagrams/Transform.hs
--- a/src/Diagrams/Transform.hs
+++ b/src/Diagrams/Transform.hs
@@ -1,6 +1,11 @@
+{-# LANGUAGE ConstraintKinds #-}
 {-# LANGUAGE MultiParamTypeClasses #-}
 {-# LANGUAGE RankNTypes            #-}
 {-# LANGUAGE TypeFamilies          #-}
+
+{-# OPTIONS_GHC -fno-warn-unused-imports #-}
+  -- for Data.Semigroup
+
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Diagrams.Transform
diff --git a/src/Diagrams/Transform/Matrix.hs b/src/Diagrams/Transform/Matrix.hs
--- a/src/Diagrams/Transform/Matrix.hs
+++ b/src/Diagrams/Transform/Matrix.hs
@@ -1,5 +1,7 @@
-{-# LANGUAGE CPP            #-}
-{-# LANGUAGE MonoLocalBinds #-}
+{-# LANGUAGE ConstraintKinds #-}
+{-# LANGUAGE CPP             #-}
+{-# LANGUAGE MonoLocalBinds  #-}
+{-# LANGUAGE TypeFamilies    #-}
 
 -----------------------------------------------------------------------------
 -- |
diff --git a/src/Diagrams/TwoD/Adjust.hs b/src/Diagrams/TwoD/Adjust.hs
--- a/src/Diagrams/TwoD/Adjust.hs
+++ b/src/Diagrams/TwoD/Adjust.hs
@@ -1,7 +1,11 @@
+{-# LANGUAGE ConstraintKinds #-}
 {-# LANGUAGE FlexibleContexts #-}
 {-# LANGUAGE Rank2Types       #-}
 {-# LANGUAGE TypeFamilies     #-}
 
+{-# OPTIONS_GHC -fno-warn-unused-imports #-}
+  -- for Data.Semigroup
+
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Diagrams.TwoD.Adjust
@@ -21,14 +25,14 @@
     ) where
 
 import           Diagrams.Attributes
+import           Diagrams.BoundingBox
 import           Diagrams.Core
+import           Diagrams.Size
 import           Diagrams.TwoD.Attributes (lineTextureA)
 import           Diagrams.TwoD.Types
 import           Diagrams.Util            (( # ))
-import           Diagrams.Size
-import           Diagrams.BoundingBox
 
-import           Control.Lens             (Lens', (^.),  set)
+import           Control.Lens             (Lens', set, (^.))
 import           Data.Default.Class
 import           Data.Semigroup
 
diff --git a/src/Diagrams/TwoD/Align.hs b/src/Diagrams/TwoD/Align.hs
--- a/src/Diagrams/TwoD/Align.hs
+++ b/src/Diagrams/TwoD/Align.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE ConstraintKinds #-}
 {-# LANGUAGE FlexibleContexts #-}
 {-# LANGUAGE TypeFamilies     #-}
 
diff --git a/src/Diagrams/TwoD/Arc.hs b/src/Diagrams/TwoD/Arc.hs
--- a/src/Diagrams/TwoD/Arc.hs
+++ b/src/Diagrams/TwoD/Arc.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE ConstraintKinds #-}
 {-# LANGUAGE FlexibleContexts #-}
 {-# LANGUAGE ViewPatterns     #-}
 {-# LANGUAGE TypeFamilies     #-}
diff --git a/src/Diagrams/TwoD/Arrow.hs b/src/Diagrams/TwoD/Arrow.hs
--- a/src/Diagrams/TwoD/Arrow.hs
+++ b/src/Diagrams/TwoD/Arrow.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE ConstraintKinds #-}
 {-# LANGUAGE CPP                        #-}
 {-# LANGUAGE DeriveDataTypeable         #-}
 {-# LANGUAGE FlexibleContexts           #-}
diff --git a/src/Diagrams/TwoD/Arrowheads.hs b/src/Diagrams/TwoD/Arrowheads.hs
--- a/src/Diagrams/TwoD/Arrowheads.hs
+++ b/src/Diagrams/TwoD/Arrowheads.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE ConstraintKinds #-}
 {-# LANGUAGE FlexibleContexts          #-}
 {-# LANGUAGE NoMonomorphismRestriction #-}
 {-# LANGUAGE ScopedTypeVariables       #-}
diff --git a/src/Diagrams/TwoD/Attributes.hs b/src/Diagrams/TwoD/Attributes.hs
--- a/src/Diagrams/TwoD/Attributes.hs
+++ b/src/Diagrams/TwoD/Attributes.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE ConstraintKinds #-}
 {-# LANGUAGE CPP                        #-}
 {-# LANGUAGE DeriveDataTypeable         #-}
 {-# LANGUAGE DeriveFunctor              #-}
diff --git a/src/Diagrams/TwoD/Combinators.hs b/src/Diagrams/TwoD/Combinators.hs
--- a/src/Diagrams/TwoD/Combinators.hs
+++ b/src/Diagrams/TwoD/Combinators.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE ConstraintKinds #-}
 {-# LANGUAGE FlexibleContexts      #-}
 {-# LANGUAGE MultiParamTypeClasses #-}
 {-# LANGUAGE ScopedTypeVariables   #-}
diff --git a/src/Diagrams/TwoD/Image.hs b/src/Diagrams/TwoD/Image.hs
--- a/src/Diagrams/TwoD/Image.hs
+++ b/src/Diagrams/TwoD/Image.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE ConstraintKinds #-}
 {-# LANGUAGE DeriveDataTypeable    #-}
 {-# LANGUAGE EmptyDataDecls        #-}
 {-# LANGUAGE FlexibleContexts      #-}
diff --git a/src/Diagrams/TwoD/Model.hs b/src/Diagrams/TwoD/Model.hs
--- a/src/Diagrams/TwoD/Model.hs
+++ b/src/Diagrams/TwoD/Model.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE ConstraintKinds #-}
 {-# LANGUAGE FlexibleContexts      #-}
 {-# LANGUAGE MultiParamTypeClasses #-}
 {-# LANGUAGE TemplateHaskell       #-}
diff --git a/src/Diagrams/TwoD/Offset.hs b/src/Diagrams/TwoD/Offset.hs
--- a/src/Diagrams/TwoD/Offset.hs
+++ b/src/Diagrams/TwoD/Offset.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE ConstraintKinds #-}
 {-# LANGUAGE FlexibleContexts     #-}
 {-# LANGUAGE GADTs                #-}
 {-# LANGUAGE StandaloneDeriving   #-}
@@ -5,6 +6,9 @@
 {-# LANGUAGE TypeFamilies         #-}
 {-# LANGUAGE UndecidableInstances #-}
 {-# LANGUAGE ViewPatterns         #-}
+
+{-# OPTIONS_GHC -fno-warn-unused-imports #-}
+  -- for Data.Semigroup
 
 -----------------------------------------------------------------------------
 -- |
diff --git a/src/Diagrams/TwoD/Path.hs b/src/Diagrams/TwoD/Path.hs
--- a/src/Diagrams/TwoD/Path.hs
+++ b/src/Diagrams/TwoD/Path.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE ConstraintKinds #-}
 {-# LANGUAGE DeriveDataTypeable         #-}
 {-# LANGUAGE FlexibleContexts           #-}
 {-# LANGUAGE FlexibleInstances          #-}
diff --git a/src/Diagrams/TwoD/Points.hs b/src/Diagrams/TwoD/Points.hs
--- a/src/Diagrams/TwoD/Points.hs
+++ b/src/Diagrams/TwoD/Points.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE ConstraintKinds #-}
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Diagrams.TwoD.Points
diff --git a/src/Diagrams/TwoD/Polygons.hs b/src/Diagrams/TwoD/Polygons.hs
--- a/src/Diagrams/TwoD/Polygons.hs
+++ b/src/Diagrams/TwoD/Polygons.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE ConstraintKinds #-}
 {-# LANGUAGE CPP       #-}
 {-# LANGUAGE DeriveFunctor       #-}
 {-# LANGUAGE FlexibleContexts    #-}
diff --git a/src/Diagrams/TwoD/Segment.hs b/src/Diagrams/TwoD/Segment.hs
--- a/src/Diagrams/TwoD/Segment.hs
+++ b/src/Diagrams/TwoD/Segment.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE ConstraintKinds #-}
 {-# LANGUAGE FlexibleContexts     #-}
 {-# LANGUAGE FlexibleInstances    #-}
 {-# LANGUAGE TypeFamilies         #-}
diff --git a/src/Diagrams/TwoD/Shapes.hs b/src/Diagrams/TwoD/Shapes.hs
--- a/src/Diagrams/TwoD/Shapes.hs
+++ b/src/Diagrams/TwoD/Shapes.hs
@@ -1,6 +1,10 @@
+{-# LANGUAGE ConstraintKinds #-}
 {-# LANGUAGE FlexibleContexts #-}
 {-# LANGUAGE TemplateHaskell  #-}
 {-# LANGUAGE TypeFamilies     #-}
+
+{-# OPTIONS_GHC -fno-warn-unused-imports #-}
+  -- for Data.Semigroup
 
 -----------------------------------------------------------------------------
 -- |
diff --git a/src/Diagrams/TwoD/Size.hs b/src/Diagrams/TwoD/Size.hs
--- a/src/Diagrams/TwoD/Size.hs
+++ b/src/Diagrams/TwoD/Size.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE ConstraintKinds #-}
 {-# LANGUAGE FlexibleContexts #-}
 {-# LANGUAGE TypeFamilies     #-}
 
diff --git a/src/Diagrams/TwoD/Text.hs b/src/Diagrams/TwoD/Text.hs
--- a/src/Diagrams/TwoD/Text.hs
+++ b/src/Diagrams/TwoD/Text.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE ConstraintKinds #-}
 {-# LANGUAGE CPP                        #-}
 {-# LANGUAGE DeriveDataTypeable         #-}
 {-# LANGUAGE FlexibleContexts           #-}
diff --git a/src/Diagrams/TwoD/Transform.hs b/src/Diagrams/TwoD/Transform.hs
--- a/src/Diagrams/TwoD/Transform.hs
+++ b/src/Diagrams/TwoD/Transform.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE ConstraintKinds #-}
 {-# LANGUAGE FlexibleContexts      #-}
 {-# LANGUAGE FlexibleInstances     #-}
 {-# LANGUAGE MultiParamTypeClasses #-}
@@ -5,6 +6,10 @@
 {-# LANGUAGE TypeFamilies          #-}
 {-# LANGUAGE TypeOperators         #-}
 {-# LANGUAGE ViewPatterns          #-}
+
+{-# OPTIONS_GHC -fno-warn-unused-imports #-}
+  -- for Data.Semigroup
+
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Diagrams.TwoD.Transform
@@ -63,13 +68,13 @@
 import           Diagrams.TwoD.Types
 import           Diagrams.TwoD.Vector
 
-import           Control.Lens            hiding (at, transform)
+import           Control.Lens              hiding (at, transform)
 import           Data.Semigroup
 
 import           Linear.Affine
+import           Linear.Metric
 import           Linear.V2
 import           Linear.Vector
-import           Linear.Metric
 
 -- Rotation ------------------------------------------------
 
diff --git a/test/Diagrams/Test/Transform.hs b/test/Diagrams/Test/Transform.hs
--- a/test/Diagrams/Test/Transform.hs
+++ b/test/Diagrams/Test/Transform.hs
@@ -1,4 +1,6 @@
+{-# LANGUAGE ConstraintKinds       #-}
 {-# LANGUAGE FlexibleContexts      #-}
+{-# LANGUAGE TypeFamilies          #-}
 
 
 module Diagrams.Test.Transform where
diff --git a/test/Speed.hs b/test/Speed.hs
--- a/test/Speed.hs
+++ b/test/Speed.hs
@@ -1,4 +1,6 @@
+{-# LANGUAGE ConstraintKinds       #-}
 {-# LANGUAGE FlexibleContexts      #-}
+{-# LANGUAGE TypeFamilies          #-}
 
 module Main where