diff --git a/.github/workflows/prototyping.yml b/.github/workflows/prototyping.yml
index 916ee652..f22aa3e7 100644
--- a/.github/workflows/prototyping.yml
+++ b/.github/workflows/prototyping.yml
@@ -11,7 +11,7 @@ jobs:
     strategy:
       matrix:
         agda: ['2.6.2.1']
-        hackage: ['2022-01-31T23:42:28Z']
+        hackage: ['hackage.haskell.org,2022-01-31T23:42:28Z']
     name: prototyping
     runs-on: ubuntu-latest
     steps:
@@ -29,7 +29,7 @@ jobs:
       run: sudo apt-get install -y cabal-install
     - name: cabal update
       working-directory: prototyping
-      run: cabal v2-update hackage.haskell.org,${{ matrix.hackage }}
+      run: cabal v2-update ${{ matrix.hackage }}
     - name: cabal install
       working-directory: prototyping
       run: |