diff --git a/changelog.md b/changelog.md
--- a/changelog.md
+++ b/changelog.md
@@ -1,5 +1,11 @@
 # Hashtables changelog
 
+## 1.4.0
+
+Replace deprecated Mutable Array function, which modifies the signature of the `length`
+function and hence the API.
+Support more recent compilers.
+
 ## 1.3.1
 
 Fix Noncanonical mappend definition warning.
diff --git a/hashtables.cabal b/hashtables.cabal
--- a/hashtables.cabal
+++ b/hashtables.cabal
@@ -1,6 +1,6 @@
 Cabal-Version: 2.2
 Name:                hashtables
-Version:             1.3.1
+Version:             1.4.0
 Synopsis:            Mutable hash tables in the ST monad
 Homepage:            http://github.com/gregorycollins/hashtables
 License:             BSD-3-Clause
@@ -13,17 +13,19 @@
 
 
 tested-with:
-  GHC == 7.8.4
-  GHC == 7.10.3
-  GHC == 8.0.2
-  GHC == 8.2.2
-  GHC == 8.4.4
-  GHC == 8.6.5
-  GHC == 8.8.4
+  GHC == 9.12.0
+  GHC == 9.10.1
+  GHC == 9.8.2
+  GHC == 9.6.6
+  GHC == 9.4.8
+  GHC == 9.2.8
+  GHC == 9.0.2
   GHC == 8.10.7
-  GHC == 9.0.1
-  GHC == 9.2.4
-  GHC == 9.4.2
+  GHC == 8.8.4
+  GHC == 8.6.5
+  GHC == 8.4.4
+  GHC == 8.2.2
+  GHC == 8.0.2
 
 Description:
   This package provides a couple of different implementations of mutable hash
@@ -193,7 +195,7 @@
                      Data.HashTable.Internal.Linear.Bucket
 
   Build-depends:     base      >= 4.7 && <5,
-                     hashable  >= 1.4 && < 1.5,
+                     hashable  >= 1.4 && < 1.6,
                      primitive,
                      vector    >= 0.7 && <0.14
 
@@ -271,7 +273,7 @@
     cpp-options: -DBOUNDS_CHECKING
 
   Build-depends:     base                       >= 4     && <5,
-                     hashable                   >= 1.4 && < 1.5,
+                     hashable                   >= 1.4 && < 1.6,
                      mwc-random                 >= 0.8   && <0.16,
                      primitive,
                      QuickCheck                 >= 2.3.0.2,
diff --git a/src/Data/HashTable/Internal/IntArray.hs b/src/Data/HashTable/Internal/IntArray.hs
--- a/src/Data/HashTable/Internal/IntArray.hs
+++ b/src/Data/HashTable/Internal/IntArray.hs
@@ -106,8 +106,8 @@
 
 
 ------------------------------------------------------------------------------
-length :: IntArray s -> Int
-length (IA a) = A.sizeofMutableByteArray a `div` wordSizeInBytes
+length :: IntArray s -> ST s Int
+length (IA a) = (`div` wordSizeInBytes) <$> A.getSizeofMutableByteArray a
 
 
 ------------------------------------------------------------------------------
diff --git a/test/suite/Data/HashTable/Test/Common.hs b/test/suite/Data/HashTable/Test/Common.hs
--- a/test/suite/Data/HashTable/Test/Common.hs
+++ b/test/suite/Data/HashTable/Test/Common.hs
@@ -15,7 +15,7 @@
 import           Control.Applicative                  (pure, (<$>))
 #endif
 import           Control.Applicative                  ((<|>))
-import           Control.Monad                        (foldM_, liftM, when)
+import           Control.Monad                        (foldM_, when)
 import qualified Control.Monad                        as Monad
 import           Data.IORef
 import           Data.List                            hiding (delete, insert,
@@ -32,7 +32,7 @@
 import           Test.HUnit                           (assertEqual,
                                                        assertFailure)
 import           Test.QuickCheck                      (arbitrary, choose,
-                                                       sample')
+                                                       generate)
 import           Test.QuickCheck.Monadic              (PropertyM, assert,
                                                        forAllM, monadicIO, pre,
                                                        run)
@@ -242,7 +242,7 @@
     prop n = do
         announceQ "growTable" n
         ht <- run $ go n
-        i <- liftM head $ run $ sample' $ choose (0,n-1)
+        i <- run $ generate $ choose (0,n-1)
 
         v <- run $ lookup ht i
         assertEq ("lookup " ++ show i) (Just i) v
@@ -290,7 +290,7 @@
 
         ht <- run $ go n
 
-        i <- liftM head $ run $ sample' $ choose (4,n-1)
+        i <- run $ generate $ choose (4,n-1)
         v <- run $ lookup ht i
         assertEq ("lookup " ++ show i) (Just i) v