diff --git a/hdmedians/tests/test_geomedian.py b/hdmedians/tests/test_geomedian.py
index 0bc37e9..ff5f938 100644
--- a/hdmedians/tests/test_geomedian.py
+++ b/hdmedians/tests/test_geomedian.py
@@ -4,9 +4,9 @@ Tests.
 
 import numpy as np
 import hdmedians as hd
+import pytest
 
 from numpy.testing import assert_equal, assert_array_almost_equal
-from nose.tools import assert_true, assert_raises
 
 # shape (6, 25)
 DATA1 = np.array([[693, 990, 1281, 2101, 3524, 2577],
@@ -124,10 +124,12 @@ def test_nangeomedian_axis_one_two_good():
 def test_nangeomedian_axis_bad():
     data = np.array([[1.0, np.nan, 1.0],
                      [2.0, 1.0, 1.0]])
-    assert_raises(IndexError, hd.nangeomedian, data, axis=2)
+    with pytest.raises(IndexError):
+        hd.nangeomedian(data, axis=2)
 
 
 def test_nangeomedian_all_nan():
     data = np.array([[np.nan, np.nan, np.nan],
                      [np.nan, np.nan, np.nan]])
-    assert_raises(ValueError, hd.nangeomedian, data)
+    with pytest.raises(ValueError):
+        hd.nangeomedian(data)
diff --git a/hdmedians/tests/test_medoid.py b/hdmedians/tests/test_medoid.py
index c5e0a7f..4fbdf80 100644
--- a/hdmedians/tests/test_medoid.py
+++ b/hdmedians/tests/test_medoid.py
@@ -4,9 +4,9 @@ Tests.
 
 import numpy as np
 import hdmedians as hd
+import pytest
 
 from numpy.testing import assert_equal, assert_array_almost_equal
-from nose.tools import assert_true, assert_raises
 
 # shape (6, 25)
 DATA1 = np.array([[693, 990, 1281, 2101, 3524, 2577],
@@ -59,7 +59,7 @@ def test_medoid_in_set_random():
     s = [list(x) for x in a.T]
     m = hd.medoid(a)
     idx = s.index(list(m))
-    assert_true(idx > -1)
+    assert(idx > -1)
 
 
 def test_medoid_noaxis():
@@ -85,7 +85,8 @@ def test_medoid_axis_one():
 
 
 def test_medoid_axis_bad():
-    assert_raises(IndexError, hd.medoid, DATA1, axis=2)
+    with pytest.raises(IndexError):
+        hd.medoid(DATA1, axis=2)
 
 
 def test_medoid_noaxis_indexonly():
@@ -136,7 +137,8 @@ def test_nanmedoid_two_obs():
 def test_nanmedoid_all_nan():
     data = np.array([[np.nan, np.nan, np.nan],
                      [np.nan, np.nan, np.nan]])
-    assert_raises(ValueError, hd.nanmedoid, data)
+    with pytest.raises(ValueError):
+        hd.nanmedoid(data)
 
 
 def test_nanmedoid_axis_zero():
@@ -170,7 +172,8 @@ def test_nanmedoid_axis_one_indexonly():
 
 
 def test_nanmedoid_axis_bad():
-    assert_raises(IndexError, hd.nanmedoid, DATA1, axis=2)
+    with pytest.raises(IndexError):
+        hd.nanmedoid(DATA1, axis=2)
 
 
 def test_nanmedoid_two_obs():
@@ -184,4 +187,5 @@ def test_nanmedoid_two_obs():
 def test_nanmedoid_all_nan():
     data = np.array([[np.nan, np.nan, np.nan],
                      [np.nan, np.nan, np.nan]])
-    assert_raises(ValueError, hd.nanmedoid, data)
+    with pytest.raises(ValueError):
+        hd.nanmedoid(data)