diff --git a/.github/workflows/haskell-ci.yml b/.github/workflows/haskell-ci.yml
index 0ac6221..b575d9d 100644
--- a/.github/workflows/haskell-ci.yml
+++ b/.github/workflows/haskell-ci.yml
@@ -205,16 +205,11 @@ jobs:
           echo "package effectful" >> cabal.project
           echo "    ghc-options: -Werror=missing-methods" >> cabal.project
           cat >> cabal.project <<EOF
-          allow-newer: freer-simple:template-haskell
-          allow-newer: async:base
           allow-newer: cleff:base
           allow-newer: cleff:template-haskell
-          allow-newer: fused-effects:base
-          allow-newer: fused-effects:transformers
-          allow-newer: hashable:base
-          allow-newer: hashable:ghc-prim
-          allow-newer: polysemy:transformers
-          allow-newer: unliftio-core:base
+          allow-newer: cleff:th-abstraction
+          allow-newer: freer-simple:template-haskell
+          allow-newer: polysemy:th-abstraction
 
           package effectful
             flags: +benchmark-foreign-libraries
diff --git a/cabal.project b/cabal.project
index 9667be6..fb54258 100644
--- a/cabal.project
+++ b/cabal.project
@@ -4,7 +4,8 @@ packages:
   effectful-th/*.cabal
   effectful/*.cabal
 
--- GHC 9.4 & 9.6
 allow-newer: cleff:base
            , cleff:template-haskell
+           , cleff:th-abstraction
            , freer-simple:template-haskell
+           , polysemy:th-abstraction
diff --git a/effectful-th/effectful-th.cabal b/effectful-th/effectful-th.cabal
index ee84c58..a7d5c6a 100644
--- a/effectful-th/effectful-th.cabal
+++ b/effectful-th/effectful-th.cabal
@@ -59,7 +59,7 @@ library
                     , effectful-core      >= 1.0.0.0   && < 3.0.0.0
                     , exceptions          >= 0.10.4
                     , template-haskell    >= 2.15      && < 2.21
-                    , th-abstraction      >= 0.4       && < 0.7
+                    , th-abstraction      >= 0.6       && < 0.7
 
     hs-source-dirs:  src
 
diff --git a/effectful-th/src/Effectful/TH.hs b/effectful-th/src/Effectful/TH.hs
index 047a73c..ce48236 100644
--- a/effectful-th/src/Effectful/TH.hs
+++ b/effectful-th/src/Effectful/TH.hs
@@ -168,11 +168,7 @@ makeCon makeSig name = do
   --
   -- Sadly the version for GHC < 9 will not compile due to ambiguity error.
   let fnBody =
-        let tvFlag = \case
-              PlainTV  _ flag   -> flag
-              KindedTV _ flag _ -> flag
-
-            tyApps = (`mapMaybe` origActionVars) $ \v -> case tvFlag v of
+        let tyApps = (`mapMaybe` origActionVars) $ \v -> case tvFlag v of
               InferredSpec  -> Nothing
               SpecifiedSpec -> Just $ if maybeMonadName == Just (tvName v)
                                       then ConT ''Eff `AppT` esVar