diff --git a/lib/Data/IntArray.hs b/lib/Data/IntArray.hs
--- a/lib/Data/IntArray.hs
+++ b/lib/Data/IntArray.hs
@@ -40,7 +40,7 @@
 import GHC.ST
 import Foreign( sizeOf )
 
-#if __GLASGOW_HASKELL__ >= 78
+#if __GLASGOW_HASKELL__ >= 708
 import GHC.Exts (isTrue#)
 
 isTrue = isTrue#
diff --git a/lib/Data/Permute/MPermute.hs b/lib/Data/Permute/MPermute.hs
--- a/lib/Data/Permute/MPermute.hs
+++ b/lib/Data/Permute/MPermute.hs
@@ -78,7 +78,7 @@
 
 import Control.Monad
 import Control.Monad.ST
-#if __GLASGOW_HASKELL__ >= 78
+#if __GLASGOW_HASKELL__ >= 708
 import Control.Monad.ST.Unsafe
 #endif
 import Data.Function( on )
diff --git a/permutation.cabal b/permutation.cabal
--- a/permutation.cabal
+++ b/permutation.cabal
@@ -1,5 +1,5 @@
 name:            permutation
-version:         0.5.0.3
+version:         0.5.0.4
 homepage:        https://github.com/spacekitteh/permutation
 synopsis:        A library for permutations and combinations.
 description: