diff --git a/.github/workflows/presubmit.yml b/.github/workflows/presubmit.yml
index 02f275ff..5e1490b6 100644
--- a/.github/workflows/presubmit.yml
+++ b/.github/workflows/presubmit.yml
@@ -49,4 +49,4 @@ jobs:
 
       - name: Generate core specs (HTML only, for testing)
         run: |
-          python3 makeSpec -clean -spec core QUIET= OUTDIR=out.core -O html
+          python3 makeSpec -clean -spec core QUIET= OUTDIR=out.core -O pdf html