From 0efd90e5f01996ceb01f5a2889f9e2986322c371 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Roman=20Smr=C5=BE?= <roman.smrz@seznam.cz>
Date: Sun, 2 Aug 2026 22:22:15 +0200
Subject: Fix state consistency in MonadHead instaces

---
 src/Erebos/State.hs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'src/Erebos/State.hs')

diff --git a/src/Erebos/State.hs b/src/Erebos/State.hs
index fa58118..0f0adbe 100644
--- a/src/Erebos/State.hs
+++ b/src/Erebos/State.hs
@@ -120,7 +120,7 @@ updateLocalHead_ f = updateLocalHead (fmap (,()) . f)
 instance (HeadType a, MonadIO m) => MonadHead a (ReaderT (Head a) m) where
     updateLocalHead f = do
         h <- ask
-        snd <$> updateHead h f
+        snd <$> updateHead' h (\h' -> local (const h') (f $ headStoredObject h'))
 
 
 newtype LocalHeadT h m a = LocalHeadT { runLocalHeadT :: Storage -> Stored h -> m ( a, Stored h ) }
-- 
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