diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,12 @@
 The format is based on [Keep a Changelog](http://keepachangelog.com/)
 and this project adheres to the [Haskell Package Versioning Policy](https://pvp.haskell.org/).
 
+## [0.1.0.1] - 2020-11-30
+
+### Changed
+- Lower `cabal-version` from 3.0 to 2.2 because `stack` cannot parse 3.0
+- Replace `AtomicCounter` with `Int` (to drop the `atomic-primops` dependency)
+
 ## [0.1.0] - 2020-11-11
 
 ### Added
diff --git a/ki.cabal b/ki.cabal
--- a/ki.cabal
+++ b/ki.cabal
@@ -1,4 +1,4 @@
-cabal-version: 3.0
+cabal-version: 2.2
 
 author: Mitchell Rosen
 bug-reports: https://github.com/mitchellwrosen/ki/issues
@@ -11,7 +11,7 @@
 name: ki
 stability: experimental
 synopsis: A lightweight, structured concurrency library
-version: 0.1.0
+version: 0.1.0.1
 
 description:
   A lightweight, structured-concurrency library.
@@ -96,11 +96,11 @@
   build-depends:
     base >= 4.12.0.0 && < 4.15,
     containers,
-    stm,
+    stm
   exposed-modules:
     Ki,
     Ki.Implicit,
-    Ki.Internal,
+    Ki.Internal
   hs-source-dirs: src
   other-modules:
     Ki.CancelToken
@@ -120,9 +120,6 @@
       concurrency ^>= 1.11.0.0,
       dejafu ^>= 2.4.0.0,
     cpp-options: -DTEST
-  else
-    build-depends:
-      atomic-primops,
 
 test-suite dejafu-tests
   import: component
diff --git a/src/Ki/Concurrency.hs b/src/Ki/Concurrency.hs
--- a/src/Ki/Concurrency.hs
+++ b/src/Ki/Concurrency.hs
@@ -140,7 +140,7 @@
 import Control.Concurrent.STM hiding (registerDelay)
 import Control.Exception
 import Control.Monad (unless)
-import Data.Atomics.Counter
+import Data.IORef (IORef, atomicModifyIORef', newIORef)
 import GHC.Conc (ThreadId (ThreadId))
 #if defined(mingw32_HOST_OS)
 import GHC.Conc.Windows
@@ -177,11 +177,11 @@
 
 uniqueInt :: IO Int
 uniqueInt =
-  incrCounter 1 counter
+  atomicModifyIORef' counter \n -> let n' = n + 1 in (n', n')
 
-counter :: AtomicCounter
+counter :: IORef Int
 counter =
-  unsafePerformIO (newCounter 0)
+  unsafePerformIO (newIORef 0)
 {-# NOINLINE counter #-}
 
 #endif