diff --git a/.github/workflows/haskell.yml b/.github/workflows/haskell.yml
index 5016902..0f5070a 100644
--- a/.github/workflows/haskell.yml
+++ b/.github/workflows/haskell.yml
@@ -16,7 +16,7 @@ jobs:
       fail-fast: false
       matrix:
         os: [ubuntu-latest]
-        resolver: ['lts-20.24']
+        resolver: ['lts-19.33', 'lts-20.24', 'lts-21.18']
     steps:
       - name: git checkout
         uses: actions/checkout@v3