diff --git a/.DS_Store b/.DS_Store
index 270460b..c1fefa2 100644
Binary files a/.DS_Store and b/.DS_Store differ
diff --git a/src/.DS_Store b/src/.DS_Store
index 25a4205..7f04e6e 100644
Binary files a/src/.DS_Store and b/src/.DS_Store differ
diff --git a/src/osipi/.DS_Store b/src/osipi/.DS_Store
index b3cd699..79badd4 100644
Binary files a/src/osipi/.DS_Store and b/src/osipi/.DS_Store differ
diff --git a/tests/test_tissue.py b/tests/test_tissue.py
index e8132c5..06caa64 100755
--- a/tests/test_tissue.py
+++ b/tests/test_tissue.py
@@ -92,16 +92,16 @@ def test_tissue_extended_tofts():
     t = np.arange(0, 6 * 60, 1)
     ca = osipi.aif_parker(t)
     ct_conv = osipi.extended_tofts(t, ca, Ktrans=0, ve=0.2, vp=0.3)
-    assert math.allclose(ct_conv,ca*0.3,rtol=1e-4, atol=1e-3)
+    assert np.allclose(ct_conv,ca*0.3,rtol=1e-4, atol=1e-3)
 
     ct_exp = osipi.extended_tofts(t, ca, Ktrans=0, ve=0.2, vp=0.3, discretization_method='exp')
-    assert math.allclose(ct_conv,ca*0.3,rtol=1e-4, atol=1e-3)
+    assert np.allclose(ct_conv,ca*0.3,rtol=1e-4, atol=1e-3)
 
     ct_conv = osipi.extended_tofts(t, ca, Ktrans=0.6, ve=0, vp=0.3)
-    assert math.allclose(ct_conv,ca*0.3,rtol=1e-4, atol=1e-3)
+    assert np.allclose(ct_conv,ca*0.3,rtol=1e-4, atol=1e-3)
 
     ct_exp = osipi.extended_tofts(t, ca, Ktrans=0.6, ve=0, vp=0.3, discretization_method='exp')
-    assert math.allclose(ct_conv,ca*0.3,rtol=1e-4, atol=1e-3)
+    assert np.allclose(ct_conv,ca*0.3,rtol=1e-4, atol=1e-3)
 
 
 if __name__ == "__main__":