diff --git a/README b/README
deleted file mode 100644
--- a/README
+++ /dev/null
@@ -1,28 +0,0 @@
-This library implements 24-bit word and int types suitable for use in vector
-processing.
-
-Storable implementations are provided, however as they use a size and alignment
-of 3 bytes care should be taken to ensure they are compatible if used in
-conjunction with the FFI.
-
-These types use unboxed data and GHC primitives, and are unlikely to be
-compatible with other Haskell compilers.
-
-INSTALLATION INSTRUCTIONS
-
-This library uses the Hackage/Cabal build system.  You will need a working
-Haskell compiler and appropriate build system.  This is most easily met
-by installing the Haskell Platform.  The following command will install
-the library:
-
-cabal install iteratee
-
-This library is pure Haskell, and should install on any system with a suitable
-Haskell compiler with no extra steps required.  In particular, POSIX-compatible,
-Mac OSX, and Windows should all be supported.
-
-INSTALLATION OPTIONS:
-
-This library supports the following cabal flags:
-  splitBase (default enabled): use the split-up base package.
-
diff --git a/README.md b/README.md
new file mode 100644
--- /dev/null
+++ b/README.md
@@ -0,0 +1,30 @@
+[![Build Status](https://secure.travis-ci.org/JohnLato/word24.png?branch=master)](http://travis-ci.org/JohnLato/word24)
+
+This library implements 24-bit word and int types suitable for use in vector
+processing.
+
+Storable implementations are provided, however as they use a size and alignment
+of 3 bytes care should be taken to ensure they are compatible if used in
+conjunction with the FFI.
+
+These types use unboxed data and GHC primitives, and are unlikely to be
+compatible with other Haskell compilers.
+
+INSTALLATION INSTRUCTIONS
+
+This library uses the Hackage/Cabal build system.  You will need a working
+Haskell compiler and appropriate build system.  This is most easily met
+by installing the Haskell Platform.  The following command will install
+the library:
+
+cabal install iteratee
+
+This library is pure Haskell, and should install on any system with a suitable
+Haskell compiler with no extra steps required.  In particular, POSIX-compatible,
+Mac OSX, and Windows should all be supported.
+
+INSTALLATION OPTIONS:
+
+This library supports the following cabal flags:
+  splitBase (default enabled): use the split-up base package.
+
diff --git a/src/Data/Int/Int24.hs b/src/Data/Int/Int24.hs
--- a/src/Data/Int/Int24.hs
+++ b/src/Data/Int/Int24.hs
@@ -166,8 +166,8 @@
     x `shiftR`  i = x `shift`  (-i)
     bit n                     = case bit n of
         I32# x -> I24# (narrow24Int# x)
-    testBit  = testBitDefault
-    popCount = popCountDefault
+    testBit x i  = (x .&. bit i) /= 0
+    popCount (I24# x#) = popCount (W# (narrow24Word# (int2Word# x#)))
 
 {-# RULES
 "fromIntegral/Word8->Int24"   fromIntegral = \(W8# x#) -> I24# (word2Int# x#)
diff --git a/tests/testword24.hs b/tests/testword24.hs
--- a/tests/testword24.hs
+++ b/tests/testword24.hs
@@ -133,9 +133,13 @@
 prop_comp a = complement (complement a) == a
   where types = a :: Word24
 
-prop_bit_ident q (NonNegative j) k =
-    testBit (bit j `asTypeOf` q) k == (j == k)
+prop_bit_ident q (NonNegative j) = testBit (bit j `asTypeOf` q) j == (j < 24)
 
+prop_popCount s t a = if a >= 0
+  then popCount (a `asTypeOf` s) == popCount (fromIntegral a `asTypeOf` t)
+  else
+    bitSize s - popCount (a `asTypeOf` s) == bitSize t - popCount (fromIntegral a `asTypeOf` t)
+
 -- Word Storable properties
 prop_sizeOf a = sizeOf a == 3
   where types = a :: Word24
@@ -312,6 +316,7 @@
     ,testProperty "binary rotate" prop_rotate
     ,testProperty "binary complement" prop_comp
     ,testProperty "bit/testBit" (prop_bit_ident (0::Word24))
+    ,testProperty "popCount"    (prop_popCount (0::Word24) (0::Word))
     ]
   ,testGroup "Storable instance" [
     testProperty  "sizeOf Word24" prop_sizeOf
@@ -359,6 +364,7 @@
     ,testProperty "binary rotate" prop_rotateI
     ,testProperty "binary complement" prop_compI
     ,testProperty "bit/testBit" (prop_bit_ident (0::Int24))
+    ,testProperty "popCount"    (prop_popCount (0::Int24) (0::Int))
     ]
   ,testGroup "Storable instance" [
     testProperty  "sizeOf Int24" prop_sizeOfI
diff --git a/word24.cabal b/word24.cabal
--- a/word24.cabal
+++ b/word24.cabal
@@ -1,5 +1,5 @@
 name:		word24
-version:        1.0.5
+version:        1.0.6
 synopsis:       24-bit word and int types for GHC
 description:	24-bit Word and Int data types.
 category:       Data
@@ -15,7 +15,7 @@
 build-type:     Simple
 
 extra-source-files:
-  README
+  README.md
   LICENSE
 
 library
@@ -38,7 +38,7 @@
   type: exitcode-stdio-1.0
   main-is: testword24.hs
   hs-source-dirs: tests src
-  ghc-options:    -fhpc -hpcdir dist/hpc/mix/word24-1.0.5
+  ghc-options:    -fhpc -hpcdir dist/hpc/mix/word24-1.0.6
 
   build-depends:
     base,