diff --git a/.github/workflows/haskell.yml b/.github/workflows/haskell.yml
index 3ff2ae2f3..d53964c73 100644
--- a/.github/workflows/haskell.yml
+++ b/.github/workflows/haskell.yml
@@ -37,7 +37,7 @@ jobs:
       name: Cache ~/.cabal/store
       with:
         path: ~/.cabal/store
-        key: ${{ runner.os }}-${{ matrix.ghc }}-v11-cabal-store
+        key: ${{ runner.os }}-${{ matrix.ghc }}-v9-cabal-store
 
     - uses: actions/cache@v1
       name: Cache dist-newstyle