diff --git a/python/tests/test_algorithm.py b/python/tests/test_algorithm.py
index 1d0bd4a..c45749e 100644
--- a/python/tests/test_algorithm.py
+++ b/python/tests/test_algorithm.py
@@ -574,6 +574,60 @@ class TestVerificationFail(unittest.TestCase):
             verify_optimum(ctx)
 
 
+class TestValueRange(unittest.TestCase):
+    """Test graphs that force big values for dual variables or edge slack."""
+
+    def test_big_blossom_dual(self):
+        """Force modified blossom dual close to 2*maxweight."""
+        #
+        #              [3]
+        #              / \
+        #          W-4/   \W
+        #      7     /     \
+        #  [1]-----[2]-----[4]
+        #          |   W-4
+        #         5|
+        #          |   1
+        #         [5]-----[6]
+        #
+        w = 100000
+        pairs = mwm([(1,2,7), (2,3,w-4), (2,4,w-4), (2,5,5), (3,4,w), (5,6,1)])
+        self.assertEqual(pairs, [(1,2), (3,4), (5,6)])
+
+    def test_negative_blossom_dual(self):
+        """Force modified blossom dual close to -maxweight."""
+        #
+        #              [3]
+        #              / \
+        #            5/   \7
+        #       1    /     \
+        #  [1]-----[2]-----[4]
+        #           |   5
+        #          1|
+        #           |   W
+        #          [5]-----[6]
+        #
+        w = 100000
+        pairs = mwm([(1,2,1), (2,3,5), (2,4,5), (2,5,1), (3,4,7), (5,6,w)])
+        self.assertEqual(pairs, [(1,2), (3,4), (5,6)])
+
+    def test_big_edge_slack(self):
+        """Force modified edge slack close to 3*maxweight."""
+        #
+        #      6       W      W-2      5
+        # [1]-----[2]-----[3]-----[4]-----[5]
+        #  |               |
+        #  |1              |1
+        #  |               |
+        # [6]-----[7]-----[8]-----[9]-----[10]
+        #      6       W      W-2      5
+        #
+        w = 100000
+        pairs = mwm([(1,2,6), (1,6,1), (2,3,w), (3,4,w-2), (3,8,1), (4,5,5),
+                     (6,7,6), (7,8,w), (8,9,w-2), (9,10,5)])
+        self.assertEqual(pairs, [(1,6), (2,3), (4,5), (7,8), (9,10)])
+
+
 if __name__ == "__main__":
     unittest.main()