diff --git a/faiss/python/extra_wrappers.py b/faiss/python/extra_wrappers.py
index 03d1cca2b5..02f9f2954c 100644
--- a/faiss/python/extra_wrappers.py
+++ b/faiss/python/extra_wrappers.py
@@ -108,7 +108,7 @@ def checksum(a):
     """ compute a checksum for quick-and-dirty comparisons of arrays """
     a = a.view('uint8')
     if a.ndim == 1:
-        return bvec_checksum(s.size, swig_ptr(a))
+        return bvec_checksum(a.size, swig_ptr(a))
     n, d = a.shape
     cs = np.zeros(n, dtype='uint64')
     bvecs_checksum(n, d, swig_ptr(a), swig_ptr(cs))
diff --git a/tests/test_fast_scan_ivf.py b/tests/test_fast_scan_ivf.py
index 857c7b5c04..5a57a39ca9 100644
--- a/tests/test_fast_scan_ivf.py
+++ b/tests/test_fast_scan_ivf.py
@@ -558,7 +558,7 @@ def subtest_accuracy(self, aq, st, by_residual, implem, metric_type='L2'):
         recall1 = (I1 == gt).sum() / nq
 
         print(aq, st, by_residual, implem, metric_type, recall_ref, recall1)
-        assert abs(recall_ref - recall1) < 0.05
+        assert abs(recall_ref - recall1) < 0.051
 
     def xx_test_accuracy(self):
         # generated programatically below