diff --git a/tests/test_bipartite_matching.py b/tests/test_bipartite_matching.py
index e4b25d51..057f7f9e 100644
--- a/tests/test_bipartite_matching.py
+++ b/tests/test_bipartite_matching.py
@@ -45,7 +45,7 @@ def test_empty(self):
 
         matching = maximum_bipartite_matching(adjacency, nodes1, nodes2)
 
-        self.assertIsInstance(matching, sp.spmatrix)
+        self.assertTrue(sp.issparse(matching))
         self.assertIsNot(matching, adjacency)
         self.assertEqual(matching.nnz, 0)
         self.assertEqual(matching.shape, (degree, degree))
@@ -65,7 +65,7 @@ def test_complete_bipartite(self):
 
         matching = maximum_bipartite_matching(adjacency, nodes1, nodes2)
 
-        self.assertIsInstance(matching, sp.spmatrix)
+        self.assertTrue(sp.issparse(matching))
         self.assertIsNot(matching, adjacency)
         self.assertEqual(matching.shape, (degree, degree))
         self.assert_is_unweighted_matching(matching)
@@ -85,7 +85,7 @@ def test_simple(self):
 
         matching = maximum_bipartite_matching(adjacency, nodes1, nodes2)
 
-        self.assertIsInstance(matching, sp.spmatrix)
+        self.assertTrue(sp.issparse(matching))
         self.assertIsNot(matching, adjacency)
         self.assertEqual(matching.shape, (degree, degree))
         self.assert_is_unweighted_matching(matching)
@@ -103,7 +103,7 @@ def test_simple_2(self):
 
         matching = maximum_bipartite_matching(adjacency, nodes1, nodes2)
 
-        self.assertIsInstance(matching, sp.spmatrix)
+        self.assertTrue(sp.issparse(matching))
         self.assertIsNot(matching, adjacency)
         self.assertEqual(matching.shape, (6, 6))
         self.assert_is_unweighted_matching(matching)
@@ -121,7 +121,7 @@ def test_random(self):
 
         matching = maximum_bipartite_matching(adjacency, nodes1, nodes2)
 
-        self.assertIsInstance(matching, sp.spmatrix)
+        self.assertTrue(sp.issparse(matching))
         self.assertIsNot(matching, adjacency)
         self.assertEqual(matching.shape, adjacency.shape)
         self.assert_is_unweighted_matching(matching)
@@ -132,7 +132,7 @@ def test_random_csr_matrix(self):
 
         matching = maximum_bipartite_matching(sp.csr_matrix(adjacency), nodes1, nodes2)
 
-        self.assertIsInstance(matching, sp.spmatrix)
+        self.assertTrue(sp.issparse(matching))
         self.assertIsNot(matching, adjacency)
         self.assertEqual(matching.shape, adjacency.shape)
         self.assert_is_unweighted_matching(matching)
@@ -143,7 +143,7 @@ def test_random_csr_array(self):
 
         matching = maximum_bipartite_matching(sp.csr_array(adjacency), nodes1, nodes2)
 
-        self.assertIsInstance(matching, sp.spmatrix)
+        self.assertTrue(sp.issparse(matching))
         self.assertIsNot(matching, adjacency)
         self.assertEqual(matching.shape, adjacency.shape)
         self.assert_is_unweighted_matching(matching)
@@ -154,7 +154,7 @@ def test_random_csc_array(self):
 
         matching = maximum_bipartite_matching(sp.csc_array(adjacency), nodes1, nodes2)
 
-        self.assertIsInstance(matching, sp.spmatrix)
+        self.assertTrue(sp.issparse(matching))
         self.assertIsNot(matching, adjacency)
         self.assertEqual(matching.shape, adjacency.shape)
         self.assert_is_unweighted_matching(matching)
diff --git a/tests/test_min_cost_flow.py b/tests/test_min_cost_flow.py
index 91a2f560..e4df9f50 100644
--- a/tests/test_min_cost_flow.py
+++ b/tests/test_min_cost_flow.py
@@ -89,7 +89,7 @@ def test_scipy(self):
                 [0.0, 0.0, 0.0, 0.0, 0.0, 2.0],
             ]
         )
-        self.assertIsInstance(sol, sp.spmatrix)
+        self.assertTrue(sp.issparse(sol))
         self.assertTrue(check_solution_scipy(sol, [candidate]))
 
     @unittest.skipIf(nx is None, "networkx is not installed")