diff --git a/AC-Colour.cabal b/AC-Colour.cabal
--- a/AC-Colour.cabal
+++ b/AC-Colour.cabal
@@ -1,6 +1,6 @@
 Cabal-Version: >= 1.6
 Name:          AC-Colour
-Version:       1.1.4
+Version:       1.1.5
 Stability:     Experimental
 Synopsis:      Efficient RGB colour types.
 
@@ -10,12 +10,6 @@
   both @Double@ and @Word8@ channel types. It implements
   efficient conversions between the two (GHC-specific),
   and general arithmetic over colours.
-  .
-  Changes:
-  .
-  * Added sRGB support.
-  .
-  * Minor documentation improvements.
 
 Category:      Data, Math, Numerical, Graphics
 License:       BSD3
@@ -31,7 +25,6 @@
     Data.Colour.Map
     Data.Colour.Word8
     Data.Colour.Nonlinear
-    Data.Colour.FastFloor
     Data.Colour
-  Build-Depends:   base >= 4 && < 5, ghc-prim >= 0.1.0.0 && < 0.3
+  Build-Depends:   base >= 4 && < 5
   HS-Source-Dirs:  .
diff --git a/Data/Colour.hs b/Data/Colour.hs
--- a/Data/Colour.hs
+++ b/Data/Colour.hs
@@ -31,7 +31,6 @@
 
 import Data.Colour.Double
 import Data.Colour.Word8
-import Data.Colour.FastFloor
 
 {- |
   Convert a 'Colour8' into a 'Colour'. Recall that
@@ -58,7 +57,7 @@
 cdemote :: Colour -> Colour8
 cdemote (Colour r g b) = Colour8
   {
-    red8   = fast_floor (r * 0xFF),
-    green8 = fast_floor (g * 0xFF),
-    blue8  = fast_floor (b * 0xFF)
+    red8   = floor (r * 0xFF),
+    green8 = floor (g * 0xFF),
+    blue8  = floor (b * 0xFF)
   }
diff --git a/Data/Colour/FastFloor.hs b/Data/Colour/FastFloor.hs
deleted file mode 100644
--- a/Data/Colour/FastFloor.hs
+++ /dev/null
@@ -1,35 +0,0 @@
-{-# LANGUAGE MagicHash #-}
-
-{- |
-  This module shouldn't need to exist. It exists because
-  GHC's implementation of 'floor' is currently (6.10.3)
-  very slow. See the following tickets:
-
-  <http://hackage.haskell.org/trac/ghc/ticket/1434>
-
-  <http://hackage.haskell.org/trac/ghc/ticket/2271>
--}
-
-module Data.Colour.FastFloor where
-
-import GHC.Prim
-import GHC.Types
-import GHC.Word
-
-{- |
-  This is a special version of the regular 'floor' function.
-  It works by directly calling the low-level internal GHC
-  primitives, and thus is as fast as you'd expect for such
-  a trivial operation.
-
-  (The standard 'floor' function does something crazy like
-  converting a @Double@ to a numerator/denominator @Integer@
-  pair and then computing the integer part of the quotient as
-  an @Integer@, then truncating that to a @Word8@. Which,
-  obviously, is ludicrously slow.)
-
-  Hopefully one day the need for this low-level hackery
-  will disappear.
--}
-fast_floor :: Double -> Word8
-fast_floor (D# d#) = W8# (int2Word# (double2Int# d#))