diff --git a/changelog.md b/changelog.md
--- a/changelog.md
+++ b/changelog.md
@@ -1,3 +1,7 @@
+0.4.1.4
+-------
+* Comply with NoStarIsType pragma.
+
 0.4.1.3
 -------
 * Add Semigroup ExactPi instance.
diff --git a/exact-pi.cabal b/exact-pi.cabal
--- a/exact-pi.cabal
+++ b/exact-pi.cabal
@@ -1,8 +1,5 @@
--- Initial exact-pi.cabal generated by cabal init.  For further 
--- documentation, see http://haskell.org/cabal/users-guide/
-
 name:                exact-pi
-version:             0.4.1.3
+version:             0.4.1.4
 synopsis:            Exact rational multiples of pi (and integer powers of pi)
 description:         Provides an exact representation for rational multiples of pi alongside an approximate representation of all reals.
                      Useful for storing and computing with conversion factors between physical units.
@@ -12,27 +9,25 @@
 license-file:        LICENSE
 author:              Douglas McClean
 maintainer:          douglas.mcclean@gmail.com
--- copyright:           
 category:            Data
 build-type:          Simple
 extra-source-files:  README.md,
                      changelog.md
 cabal-version:       >=1.10
 tested-with:         GHC == 7.8.4,
-                     GHC == 7.10.1,
-                     GHC == 8.0.1,
+                     GHC == 7.10.3,
                      GHC == 8.0.2,
-                     GHC == 8.2.1,
                      GHC == 8.2.2,
-                     GHC == 8.4.1
+                     GHC == 8.4.3,
+                     GHC == 8.6.1
 library
   exposed-modules:     Data.ExactPi,
                        Data.ExactPi.TypeLevel
-  -- other-modules:       
-  -- other-extensions:    
   build-depends:       base >=4.7 && <5,
-                       numtype-dk >= 0.5,
-                       semigroups >= 0.9 && < 1.0
+                       numtype-dk >= 0.5
+  if impl(ghc <8.0)
+    build-depends:
+                       semigroups >=0.8
   ghc-options:         -Wall
   hs-source-dirs:      src
   default-language:    Haskell2010
diff --git a/src/Data/ExactPi/TypeLevel.hs b/src/Data/ExactPi/TypeLevel.hs
--- a/src/Data/ExactPi/TypeLevel.hs
+++ b/src/Data/ExactPi/TypeLevel.hs
@@ -1,6 +1,7 @@
 {-# OPTIONS_HADDOCK show-extensions #-}
 
 {-# LANGUAGE ConstraintKinds #-}
+{-# LANGUAGE CPP #-}
 {-# LANGUAGE DataKinds #-}
 {-# LANGUAGE FlexibleContexts #-}
 {-# LANGUAGE KindSignatures #-}
@@ -8,6 +9,10 @@
 {-# LANGUAGE TypeFamilies #-}
 {-# LANGUAGE TypeOperators #-}
 
+#if __GLASGOW_HASKELL__ > 805
+{-# LANGUAGE NoStarIsType #-}
+#endif
+
 {-|
 Module      : Data.ExactPi.TypeLevel
 Description : Exact non-negative rational multiples of powers of pi at the type level
@@ -16,7 +21,7 @@
 Stability   : experimental
 
 This kind is sufficient to exactly express the closure of Q⁺ ∪ {π} under multiplication and division.
-As a result it is useful for representing conversion factors between physical units. 
+As a result it is useful for representing conversion factors between physical units.
 -}
 module Data.ExactPi.TypeLevel
 (
@@ -37,7 +42,6 @@
 import Data.Maybe (fromJust)
 import Data.Proxy
 import Data.Ratio
-import GHC.Exts (Constraint)
 import GHC.TypeLits hiding (type (*), type (^))
 import qualified GHC.TypeLits as N
 import Numeric.NumType.DK.Integers hiding (type (*), type (/))
@@ -69,7 +73,7 @@
 
 -- | Determines the minimum context required for a numeric type to hold the value
 -- associated with a specific 'ExactPi'' type.
-type family MinCtxt' (v :: ExactPi') :: * -> Constraint where
+type family MinCtxt' (v :: ExactPi') where
   MinCtxt' ('ExactPi' 'Zero p 1) = Num
   MinCtxt' ('ExactPi' 'Zero p q) = Fractional
   MinCtxt' ('ExactPi' z p q)     = Floating
@@ -78,9 +82,9 @@
 
 -- | A KnownMinCtxt is a contraint on values sufficient to allow us to inject certain
 -- 'ExactPi' values into types that satisfy the constraint.
-class KnownMinCtxt (c :: * -> Constraint) where
+class KnownMinCtxt c where
   -- | Injects an 'ExactPi' value into a specified type satisfying this constraint.
-  -- 
+  --
   -- The injection is permitted to fail if type constraint does not entail the 'MinCtxt'
   -- required by the 'ExactPi'' representation of the supplied 'ExactPi' value.
   inj :: c a => Proxy c -- ^ A proxy for identifying the required constraint.
@@ -97,7 +101,7 @@
   inj _ = approximateValue
 
 -- | Converts an 'ExactPi'' type to a numeric value with the minimum required context.
--- 
+--
 -- When the value is known to be an integer, it can be returned as any instance of 'Num'. Similarly,
 -- rationals require 'Fractional', and values that involve 'pi' require 'Floating'.
 injMin :: forall v a.(MinCtxt v a) => Proxy v -> a