diff --git a/.github/workflows/run_tests.yml b/.github/workflows/run_tests.yml
index 0eef4171..7be82e72 100644
--- a/.github/workflows/run_tests.yml
+++ b/.github/workflows/run_tests.yml
@@ -1,6 +1,8 @@
 name: Run tests
 run-name: Run tests - ${{ github.sha }}
 on: push
+env:
+  OPENBLAS_NUM_THREADS: 1
 jobs:
   run_test:
     strategy:
@@ -41,11 +43,6 @@ jobs:
           python-version: ${{ matrix.config.py }}
       - name: Install dmri-commit
         run: pip install . --no-cache-dir --force-reinstall
-      - name: Print info
-        run: |
-          gcc --version
-          python -V
-          pip list
       - name: Run test
         id: run_test
         working-directory: tests
diff --git a/commit/operator/operator.pyxbld b/commit/operator/operator.pyxbld
index 91b90c93..f3967a15 100644
--- a/commit/operator/operator.pyxbld
+++ b/commit/operator/operator.pyxbld
@@ -36,4 +36,4 @@ def make_ext(modname, pyxfilename):
                                     ('nIC', config.nIC),
                                     ('nEC', config.nEC),
                                     ('nISO', config.nISO)],
-                     extra_compile_args=['-w', '-O3'])
+                     extra_compile_args=['-w', '-O3', '-Ofast'])
diff --git a/tests/demo_data/ref_results/ref_results_BallandStick.pickle b/tests/demo_data/ref_results/ref_results_BallandStick.pickle
index 661a5da7..c0b7bde4 100644
Binary files a/tests/demo_data/ref_results/ref_results_BallandStick.pickle and b/tests/demo_data/ref_results/ref_results_BallandStick.pickle differ
diff --git a/tests/demo_data/ref_results/ref_results_StickZeppelinBall.pickle b/tests/demo_data/ref_results/ref_results_StickZeppelinBall.pickle
index 9e95097b..7435916c 100644
Binary files a/tests/demo_data/ref_results/ref_results_StickZeppelinBall.pickle and b/tests/demo_data/ref_results/ref_results_StickZeppelinBall.pickle differ
diff --git a/tests/test_demo.py b/tests/test_demo.py
index 3bb66a30..cf810ed8 100644
--- a/tests/test_demo.py
+++ b/tests/test_demo.py
@@ -116,12 +116,12 @@ def check_results(pickle_result, ref_pickle):
     result_optimization = data[0]["optimization"]
     ref_optimization = ref_data[0]["optimization"]
     print(result_optimization["fit_details"])
-    # print(ref_optimization["fit_details"])
-    # try:
-    #     assert result_optimization["fit_details"] == ref_optimization["fit_details"]
-    # except AssertionError:
-    #     print("fit_details are not equal")
-    #     sys.exit(1)
+    print(ref_optimization["fit_details"])
+    try:
+        assert result_optimization["fit_details"] == ref_optimization["fit_details"]
+    except AssertionError:
+        print("fit_details are not equal")
+        sys.exit(1)
 
 
 def run_tests():
@@ -132,9 +132,9 @@ def run_tests():
     run_commit_StickZeppelinBall(local_path)
     results_pickle = os.path.join( local_path, 'COMMIT', 'Results_StickZeppelinBall', 'results.pickle' )
     check_results(results_pickle, ref_pickle_StickZeppelinBall)
-    # run_commit_BallandStick(local_path)
-    # results_pickle = os.path.join( local_path, 'COMMIT', 'Results_StickZeppelinBall', 'results.pickle' )
-    # check_results(results_pickle, ref_pickle_BallandStick)
+    run_commit_BallandStick(local_path)
+    results_pickle = os.path.join( local_path, 'COMMIT', 'Results_StickZeppelinBall', 'results.pickle' )
+    check_results(results_pickle, ref_pickle_BallandStick)
     # run_commit_VolumeFractions()
     # results_pickle = os.path.join( local_path, 'demo_data', 'COMMIT', 'Results_VolumeFractions', 'results.pickle' )
     # check_results(results_pickle, ref_pickle_VolumeFractions)