diff --git a/.github/workflows/test-suite.yml b/.github/workflows/test-suite.yml
index 6844fafb113..70d5ad99ff4 100644
--- a/.github/workflows/test-suite.yml
+++ b/.github/workflows/test-suite.yml
@@ -51,7 +51,7 @@ jobs:
   release-tests-ubuntu:
     name: release-tests-ubuntu
     # Use self-hosted runners only on the sigp repo.
-    runs-on: ${{ github.repository == 'sigp/lighthouse' && '[self-hosted, linux, large]' || 'ubuntu-latest'  }}
+    runs-on: ${{ github.repository == 'sigp/lighthouse' && fromJson('["self-hosted", "linux", "large"]') || 'ubuntu-latest'  }}
     needs: cargo-fmt
     steps:
     - uses: actions/checkout@v3
@@ -104,7 +104,7 @@ jobs:
   beacon-chain-tests:
     name: beacon-chain-tests
     # Use self-hosted runners only on the sigp repo.
-    runs-on: ${{ github.repository == 'sigp/lighthouse' && '[self-hosted, linux, large]' || 'ubuntu-latest'  }}
+    runs-on: ${{ github.repository == 'sigp/lighthouse' && fromJson('["self-hosted", "linux", "large"]') || 'ubuntu-latest'  }}
     needs: cargo-fmt
     steps:
     - uses: actions/checkout@v3