diff --git a/dipy/reconst/tests/test_ivim.py b/dipy/reconst/tests/test_ivim.py
index 10ce9a60cd..9c8ea99950 100644
--- a/dipy/reconst/tests/test_ivim.py
+++ b/dipy/reconst/tests/test_ivim.py
@@ -185,7 +185,8 @@ def test_mask():
     Test whether setting incorrect mask raises and error
     """
     mask_correct = data_multi[..., 0] > 0.2
-    mask_not_correct = np.array([[False, True, False], [True, False]])
+    mask_not_correct = np.array([[False, True, False], [True, False]],
+                                dtype=np.bool)
 
     ivim_fit = ivim_model_trr.fit(data_multi, mask_correct)
     est_signal = ivim_fit.predict(gtab, S0=1.)