diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,5 +1,12 @@
 # ChangeLog for auto-update
 
+## 0.2.8
+
+* use `atomicWriteIORef` instead of `writeIORef` in the following modules to
+  avoid more issues: [#1112](https://github.com/yesodweb/wai/pull/1112)
+    * `Control.Reaper` (`spawn` & `reaper`)
+    * `Control.AutoUpdate.Event` (`getUpdateResult`)
+
 ## 0.2.7
 
 * Use `atomicModifyIORef` in `mkAutoUpdate(Helper)` to prevent race conditions
diff --git a/Control/AutoUpdate/Event.hs b/Control/AutoUpdate/Event.hs
--- a/Control/AutoUpdate/Event.hs
+++ b/Control/AutoUpdate/Event.hs
@@ -119,6 +119,7 @@
 getUpdateResult :: UpdateState a -> IO a
 getUpdateResult us@UpdateState{..} = do
     onceOnTimeHasCome us $ do
-        writeIORef usLastResult_ =<< usUpdateAction_ =<< readIORef usLastResult_
-        writeIORef usDeleteTimeout_ =<< mkDeleteTimeout usTimeHasCome_ usIntervalMicro_
+        atomicWriteIORef usLastResult_ =<< usUpdateAction_ =<< readIORef usLastResult_
+        atomicWriteIORef usDeleteTimeout_
+            =<< mkDeleteTimeout usTimeHasCome_ usIntervalMicro_
     readIORef usLastResult_
diff --git a/Control/AutoUpdate/Thread.hs b/Control/AutoUpdate/Thread.hs
--- a/Control/AutoUpdate/Thread.hs
+++ b/Control/AutoUpdate/Thread.hs
@@ -20,7 +20,7 @@
     try,
  )
 import Control.Monad (void)
-import Data.IORef (newIORef, readIORef, writeIORef, atomicWriteIORef)
+import Data.IORef (atomicWriteIORef, newIORef, readIORef, writeIORef)
 import Data.Maybe (fromMaybe)
 import GHC.Conc.Sync (labelThread)
 
diff --git a/Control/Reaper.hs b/Control/Reaper.hs
--- a/Control/Reaper.hs
+++ b/Control/Reaper.hs
@@ -45,7 +45,13 @@
 import Control.Concurrent (ThreadId, forkIO, killThread, threadDelay)
 import Control.Exception (mask_)
 import Control.Reaper.Internal
-import Data.IORef (IORef, atomicModifyIORef', newIORef, readIORef, writeIORef)
+import Data.IORef (
+    IORef,
+    atomicModifyIORef',
+    atomicWriteIORef,
+    newIORef,
+    readIORef,
+ )
 import GHC.Conc.Sync (labelThread)
 
 -- | Settings for creating a reaper. This type has two parameters:
@@ -190,7 +196,7 @@
 spawn settings stateRef tidRef = do
     tid <- forkIO $ reaper settings stateRef tidRef
     labelThread tid $ reaperThreadName settings
-    writeIORef tidRef $ Just tid
+    atomicWriteIORef tidRef $ Just tid
 
 reaper
     :: ReaperSettings workload item
@@ -211,7 +217,7 @@
         then
             reaper settings stateRef tidRef
         else
-            writeIORef tidRef Nothing
+            atomicWriteIORef tidRef Nothing
   where
     swapWithEmpty NoReaper = error "Control.Reaper.reaper: unexpected NoReaper (1)"
     swapWithEmpty (Workload wl) = (Workload reaperEmpty, wl)
diff --git a/auto-update.cabal b/auto-update.cabal
--- a/auto-update.cabal
+++ b/auto-update.cabal
@@ -1,5 +1,5 @@
 name:                auto-update
-version:             0.2.7
+version:             0.2.8
 synopsis:            Efficiently run periodic, on-demand actions
 description:         API docs and the README are available at <http://www.stackage.org/package/auto-update>.
 homepage:            https://github.com/yesodweb/wai