diff --git a/Data/CAS.hs b/Data/CAS.hs
--- a/Data/CAS.hs
+++ b/Data/CAS.hs
@@ -3,7 +3,7 @@
 
 -- | Atomic compare and swap for IORefs and STRefs.
 module Data.CAS 
- ( casSTRef, casIORef,
+ ( casSTRef, casIORef, ptrEq,
    atomicModifyIORefCAS, atomicModifyIORefCAS_,
 
    -- * Generic interface: for interoperation with `Fake` and `Foreign` alternative libraries.
@@ -32,6 +32,9 @@
 -- | Performs a machine-level compare and swap operation on an
 -- 'STRef'. Returns a tuple containing a 'Bool' which is 'True' when a
 -- swap is performed, along with the 'current' value from the 'STRef'.
+-- 
+-- Note \"compare\" here means pointer equality in the sense of
+-- 'GHC.Prim.reallyUnsafePtrEquality#'.
 casSTRef :: STRef s a -- ^ The 'STRef' containing a value 'current'
          -> a -- ^ The 'old' value to compare
          -> a -- ^ The 'new' value to replace 'current' if @old == current@
@@ -46,6 +49,9 @@
 -- | Performs a machine-level compare and swap operation on an
 -- 'IORef'. Returns a tuple containing a 'Bool' which is 'True' when a
 -- swap is performed, along with the 'current' value from the 'IORef'.
+-- 
+-- Note \"compare\" here means pointer equality in the sense of
+-- 'GHC.Prim.reallyUnsafePtrEquality#'.
 casIORef :: IORef a -- ^ The 'IORef' containing a value 'current'
          -> a -- ^ The 'old' value to compare
          -> a -- ^ The 'new' value to replace 'current' if @old == current@
diff --git a/IORefCAS.cabal b/IORefCAS.cabal
--- a/IORefCAS.cabal
+++ b/IORefCAS.cabal
@@ -1,5 +1,5 @@
 Name:                IORefCAS
-Version:             0.0.1.2
+Version:             0.1.0.1
 License:             BSD3
 License-file:        LICENSE
 Author:              Adam C. Foltzer, Ryan Newton
@@ -12,6 +12,7 @@
 -- 0.0.1   -- initial release
 -- 0.0.1.1 -- minor bump to include README
 -- 0.0.1.2 -- Egad, super minor update.
+-- 0.1.0.1 -- Include ptrEq in Data.CAS
 
 Synopsis: Atomic compare and swap for IORefs and STRefs.