diff --git a/contrib/evaluation.py b/contrib/evaluation.py
index 927c88e66..6ed969b81 100644
--- a/contrib/evaluation.py
+++ b/contrib/evaluation.py
@@ -244,10 +244,10 @@ def _cluster_tables_with_tolerance(tab1, tab2, thr):
     return idx1, idx2
 
 
-def check_ref_knn_with_draws(Dref, Iref, Dnew, Inew, rtol=1e-5):
+def check_ref_knn_with_draws(Dref, Iref, Dnew, Inew, rtol=1e-5, atol=0):
     """test that knn search results are identical, with possible ties.
     Raise if not."""
-    np.testing.assert_allclose(Dref, Dnew, rtol=rtol)
+    np.testing.assert_allclose(Dref, Dnew, rtol=rtol, atol=atol)
     # here we have to be careful because of draws
     testcase = unittest.TestCase()  # because it makes nice error messages
     for i in range(len(Iref)):
@@ -255,7 +255,7 @@ def check_ref_knn_with_draws(Dref, Iref, Dnew, Inew, rtol=1e-5):
             continue
 
         # otherwise collect elements per distance
-        r = rtol * Dref[i].max()
+        r = rtol * Dref[i].max() + atol
 
         DrefC, DnewC = _cluster_tables_with_tolerance(Dref[i], Dnew[i], r)
 
diff --git a/tests/test_ivf_flat_panorama.py b/tests/test_ivf_flat_panorama.py
index 638f69f82..4c250b04d 100644
--- a/tests/test_ivf_flat_panorama.py
+++ b/tests/test_ivf_flat_panorama.py
@@ -105,7 +105,7 @@ class TestIndexIVFFlatPanorama(unittest.TestCase):
             err_msg="Distances mismatch",
         )
         check_ref_knn_with_draws(
-            D_regular, I_regular, D_regular, I_panorama, rtol=rtol
+            D_regular, I_regular, D_panorama, I_panorama, rtol=rtol, atol=atol
         )
 
     def assert_range_results_equal(
diff --git a/tests/test_refine_panorama.py b/tests/test_refine_panorama.py
index a8555a7fa..889b511ac 100644
--- a/tests/test_refine_panorama.py
+++ b/tests/test_refine_panorama.py
@@ -91,7 +91,7 @@ class TestIndexRefinePanorama(unittest.TestCase):
             err_msg="Distances mismatch",
         )
         check_ref_knn_with_draws(
-            D_regular, I_regular, D_regular, I_panorama, rtol=rtol
+            D_regular, I_regular, D_panorama, I_panorama, rtol=rtol, atol=atol
         )
 
     def test_refine_panorama_correctness(self):