diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,9 @@
 # Changelog for Color
 
+## 0.3.1
+
+* Remove `RealFloat` constraint from `ColorSpace` for `Y'`
+
 ## 0.3.0
 
 * Rename `Y` color model into `X` to avoid the annoying name conflict.
diff --git a/Color.cabal b/Color.cabal
--- a/Color.cabal
+++ b/Color.cabal
@@ -1,5 +1,5 @@
 name:                Color
-version:             0.3.0
+version:             0.3.1
 synopsis:            Color spaces and conversions between them
 description:         Please see the README on GitHub at <https://github.com/lehins/Color#readme>
 homepage:            https://github.com/lehins/Color
@@ -19,7 +19,8 @@
                     , GHC == 8.6.3
                     , GHC == 8.6.4
                     , GHC == 8.6.5
-                    , GHC == 8.8.3
+                    , GHC == 8.8.4
+                    , GHC == 8.10.4
 
 library
   hs-source-dirs:      src
diff --git a/README.md b/README.md
--- a/README.md
+++ b/README.md
@@ -5,9 +5,9 @@
 
 ## Status
 
-| Language | Travis | Azure | Coveralls |Gitter.im |
-|:--------:|:------:|:--------:|:---------:|:--------:|
-| ![GitHub top language](https://img.shields.io/github/languages/top/lehins/Color.svg) | [![Travis](https://img.shields.io/travis/lehins/Color/master.svg?label=Linux%20%26%20OS%20X)](https://travis-ci.org/lehins/Color) | [![Build Status](https://dev.azure.com/kuleshevich/Color/_apis/build/status/lehins.Color?branchName=master)](https://dev.azure.com/kuleshevich/Color/_build?branchName=master) | [![Coverage Status](https://coveralls.io/repos/github/lehins/Color/badge.svg?branch=master)](https://coveralls.io/github/lehins/Color?branch=master) | [![Join the chat at https://gitter.im/haskell-massiv/Lobby](https://badges.gitter.im/haskell-massiv/Lobby.svg)](https://gitter.im/haskell-massiv/Lobby?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
+| Language | Github Actions | Coveralls |Gitter.im |
+|:--------:|:--------------:|:---------:|:--------:|
+| ![GitHub top language](https://img.shields.io/github/languages/top/lehins/Color.svg) | [![Build Status](https://github.com/lehins/Color/workflows/Color-CI/badge.svg)](https://github.com/lehins/Color/actions) | [![Coverage Status](https://coveralls.io/repos/github/lehins/Color/badge.svg?branch=master)](https://coveralls.io/github/lehins/Color?branch=master) | [![Join the chat at https://gitter.im/haskell-massiv/Lobby](https://badges.gitter.im/haskell-massiv/Lobby.svg)](https://gitter.im/haskell-massiv/Lobby?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
 
 |      Package       | Hackage | Nightly | LTS |
 |:-------------------|:-------:|:-------:|:---:|
diff --git a/src/Graphics/Color/Space/RGB/Luma.hs b/src/Graphics/Color/Space/RGB/Luma.hs
--- a/src/Graphics/Color/Space/RGB/Luma.hs
+++ b/src/Graphics/Color/Space/RGB/Luma.hs
@@ -104,18 +104,17 @@
          , ColorSpace (cs 'NonLinear) i e
          , Luma cs
          , RedGreenBlue cs i
-         , RealFloat e
          ) =>
          ColorSpace (Y' cs) i e where
   type BaseModel (Y' cs) = CM.X
   type BaseSpace (Y' cs) = cs 'NonLinear
   toBaseSpace y = pure (coerce y :: e)
   {-# INLINE toBaseSpace #-}
-  fromBaseSpace = rgbLuma
+  fromBaseSpace = fmap fromDouble . rgbLuma
   {-# INLINE fromBaseSpace #-}
-  luminance = luminance . toBaseLinearSpace
+  luminance = luminance . fmap (fromDouble :: Double -> e) . toBaseLinearSpace . fmap toDouble
   {-# INLINE luminance #-}
-  toColorXYZ = toColorXYZ . toBaseLinearSpace
+  toColorXYZ = toColorXYZ . fmap (fromDouble :: Double -> e) . toBaseLinearSpace . fmap toDouble
   {-# INLINE toColorXYZ #-}
 
 -- | Convert Luma directly into the linear version of base space. This is equivalent to
diff --git a/tests/doctests.hs b/tests/doctests.hs
--- a/tests/doctests.hs
+++ b/tests/doctests.hs
@@ -1,6 +1,16 @@
+{-# LANGUAGE CPP #-}
 module Main where
 
+#if __GLASGOW_HASKELL__ >= 802 && __GLASGOW_HASKELL__ < 810
+
 import Test.DocTest (doctest)
 
 main :: IO ()
 main = doctest ["src"]
+
+#else
+
+main :: IO ()
+main = putStrLn "\nDoctests are not supported for older ghc version\n"
+
+#endif