diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,3 +1,7 @@
+# v1.1.2.5
+
+- Fixes Accum carriers (Strict and Church) to not duplicate state ([#449](https://github.com/fused-effects/fused-effects/issues/449)) (by @byorgey)
+
 # v1.1.2.4
 
 - Adds support for `ghc` 9.12 and `base` 4.21.
diff --git a/fused-effects.cabal b/fused-effects.cabal
--- a/fused-effects.cabal
+++ b/fused-effects.cabal
@@ -1,7 +1,7 @@
 cabal-version:       2.2
 
 name:                fused-effects
-version:             1.1.2.4
+version:             1.1.2.5
 synopsis:            A fast, flexible, fused effect system.
 description:         A fast, flexible, fused effect system, à la Effect Handlers in Scope, Monad Transformers and Modular Algebraic Effects: What Binds Them Together, and Fusion for Free—Efficient Algebraic Effect Handlers.
 homepage:            https://github.com/fused-effects/fused-effects
diff --git a/src/Control/Carrier/Accum/Church.hs b/src/Control/Carrier/Accum/Church.hs
--- a/src/Control/Carrier/Accum/Church.hs
+++ b/src/Control/Carrier/Accum/Church.hs
@@ -129,5 +129,5 @@
     L accum -> case accum of
       Add w' -> k w' ctx
       Look   -> k mempty $ w <$ ctx
-    R other  -> thread (uncurry (runAccum (curry pure)) ~<~ hdl) other (w, ctx) >>= uncurry k
+    R other  -> thread (uncurry (runAccum (curry pure)) ~<~ hdl) other (mempty, ctx) >>= uncurry k
   {-# INLINE alg #-}
diff --git a/src/Control/Carrier/Accum/Strict.hs b/src/Control/Carrier/Accum/Strict.hs
--- a/src/Control/Carrier/Accum/Strict.hs
+++ b/src/Control/Carrier/Accum/Strict.hs
@@ -132,5 +132,5 @@
     L accum -> case accum of
       Add w' -> pure (w', ctx)
       Look   -> pure (mempty, w <$ ctx)
-    R other  -> thread (uncurry runAccum ~<~ hdl) other (w, ctx)
+    R other  -> thread (uncurry runAccum ~<~ hdl) other (mempty, ctx)
   {-# INLINE alg #-}