diff --git a/skgstat/MetricSpace.py b/skgstat/MetricSpace.py
index 3a3361e..c535313 100644
--- a/skgstat/MetricSpace.py
+++ b/skgstat/MetricSpace.py
@@ -777,14 +777,16 @@ def dists(self):
             # from https://stackoverflow.com/questions/28677162/ignoring-duplicate-entries-in-sparse-matrix
 
             # Stable solution but a bit slow
-            # c, eq, d = zip(*set(zip(c, eq, d)))
-            # dists = sparse.csr_matrix((d, (c, eq)), shape=(len(self.coords), len(self.coords)))
+            c, eq, d = zip(*set(zip(c, eq, d)))
+            dists = sparse.csr_matrix((d, (c, eq)), shape=(len(self.coords), len(self.coords)))
 
+            # comment mmaelicke: We need to fall back to the slower solution as dok._update is not supported in scipy 1.0 anymore
+            # 
             # Solution 5+ times faster than the preceding, but relies on _update() which might change in scipy (which
             # only has an implemented method for summing duplicates, and not ignoring them yet)
-            dok = sparse.dok_matrix((len(self.coords), len(self.coords)))
-            dok._update(zip(zip(c, eq), d))
-            dists = dok.tocsr()
+            # dok = sparse.dok_matrix((len(self.coords), len(self.coords)))
+            # dok._update(zip(zip(c, eq), d))
+            # dists = dok.tocsr()
 
             self._dists = dists
 
diff --git a/skgstat/tests/test_variogram.py b/skgstat/tests/test_variogram.py
index f1a6273..68020f6 100644
--- a/skgstat/tests/test_variogram.py
+++ b/skgstat/tests/test_variogram.py
@@ -896,7 +896,7 @@ def test_harmonize_model(self):
 
         assert_array_almost_equal(
             V.transform(x),
-            [np.NaN, 0.57, 1.01, 1.12, 1.15, 1.15, 1.15, 1.15, 1.21, 1.65],
+            [np.nan, 0.57, 1.01, 1.12, 1.15, 1.15, 1.15, 1.15, 1.21, 1.65],
             decimal=2
         )