diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,9 @@
 # Changelog for the [`ghc-typelits-natnormalise`](http://hackage.haskell.org/package/ghc-typelits-natnormalise) package
 
+## 0.9.1 *October 21st 2025*
+* Fixes [#105](https://github.com/clash-lang/ghc-typelits-natnormalise/issues/105) Unsound derived contradiction with 0.9.0
+* Support for GHC 9.14
+
 ## 0.9.0 *October 17th 2025*
 * Drop `TyConSubst` argument from `normaliseNat`, `normaliseNatEverywhere` and `normaliseSimplifyNat`.
 * Expose `GHC.TypeLits.Normalise.Compat`
diff --git a/ghc-typelits-natnormalise.cabal b/ghc-typelits-natnormalise.cabal
--- a/ghc-typelits-natnormalise.cabal
+++ b/ghc-typelits-natnormalise.cabal
@@ -1,6 +1,6 @@
 cabal-version:       3.0
 name:                ghc-typelits-natnormalise
-version:             0.9.0
+version:             0.9.1
 synopsis:            GHC typechecker plugin for types of kind GHC.TypeLits.Nat
 description:
   A type checker plugin for GHC that can solve /equalities/ and /inequalities/
@@ -68,7 +68,7 @@
                        GHC.TypeLits.Normalise.SOP,
                        GHC.TypeLits.Normalise.Unify
   build-depends:       base                >=4.9   && <5,
-                       containers          >=0.5.7.1 && <0.8,
+                       containers          >=0.5.7.1 && <0.9,
                        ghc                 >=8.8.1 && <9.15,
                        ghc-tcplugin-api    >=0.18.0 && <0.19,
                        transformers        >=0.5.2.0 && < 0.7
diff --git a/src/GHC/TypeLits/Normalise/Unify.hs b/src/GHC/TypeLits/Normalise/Unify.hs
--- a/src/GHC/TypeLits/Normalise/Unify.hs
+++ b/src/GHC/TypeLits/Normalise/Unify.hs
@@ -788,7 +788,7 @@
   = any canBeZero bs
   | otherwise
   = True
-canBeZero (V v) = isMetaTyVar v -- e.g. 'tau' where 'tau' is an unfilled metavariable
+canBeZero (V {}) = True -- e.g. 'tau' where 'tau' is an unfilled metavariable
 
 -- | Try to solve inequalities
 solveIneq