diff --git a/.github/workflows/hlint.yaml b/.github/workflows/hlint.yaml
index a63bd26..5cbbe22 100644
--- a/.github/workflows/hlint.yaml
+++ b/.github/workflows/hlint.yaml
@@ -6,7 +6,7 @@ on:
 
 jobs:
   hlint:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04  # FIXME
     steps:
     - uses: actions/checkout@v3
 
diff --git a/.github/workflows/nix.yml b/.github/workflows/nix.yml
index 8f8a716..b5ee40b 100644
--- a/.github/workflows/nix.yml
+++ b/.github/workflows/nix.yml
@@ -6,7 +6,7 @@ on:
 
 jobs:
   build:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04  # FIXME
     name: Nix Flake - Linux
     permissions:
       contents: read