diff --git a/.github/workflows/presubmit.yml b/.github/workflows/presubmit.yml
index 5e1490b6..fe0a9b89 100644
--- a/.github/workflows/presubmit.yml
+++ b/.github/workflows/presubmit.yml
@@ -47,6 +47,10 @@ jobs:
         run: |
           make -C xml validate
 
-      - name: Generate core specs (HTML only, for testing)
+      - name: Generate core specs (full, single threaded)
         run: |
-          python3 makeSpec -clean -spec core QUIET= OUTDIR=out.core -O pdf html
+          python3 makeSpec -clean -spec core QUIET= OUTDIR=out.core/full-nopar -O api c env ext cxx4opencl
+
+      - name: Generate core specs (full, -j)
+        run: |
+          python3 makeSpec -clean -spec core QUIET= OUTDIR=out.core/full-par -O -j 5 api c env ext cxx4opencl