diff --git a/.github/workflows/test_full.yml b/.github/workflows/test_full.yml
index 97d13280..8b71081a 100644
--- a/.github/workflows/test_full.yml
+++ b/.github/workflows/test_full.yml
@@ -30,16 +30,19 @@ jobs:
         run: |
           python -m pip install -U pip
           pip install -r prereq.txt
-      - name: Test Core - slow part one
-        timeout-minutes: 1000
+      - name: Limit OpenMP threads
         run: |
-          pip install .[testing]
-          pytest -vvvs --durations=50 -m "slow_1"
-      - name: Test Core - slow part two
-        timeout-minutes: 1000
+          echo "OMP_NUM_THREADS=2" >> $GITHUB_ENV
+      - name: Test Core - slow
+        # timeout-minutes: 1000
         run: |
           pip install .[testing]
-          pytest -vvvs --durations=50 -m "slow_2"
+          pytest -vvvs --durations=50 -m "slow"
+      # - name: Test Core - slow part two
+      #   timeout-minutes: 1000
+      #   run: |
+      #     pip install .[testing]
+      #     pytest -vvvs --durations=50 -m "slow_2"
       - name: Test Core - fast
         timeout-minutes: 1000
         run: |