1 files changed, 6 insertions, 0 deletions
diff --git a/Lib/test/test_dumbdbm.py b/Lib/test/test_dumbdbm.py
index efdee75..d5a74fb 100644
--- a/Lib/test/test_dumbdbm.py
+++ b/Lib/test/test_dumbdbm.py
@@ -89,6 +89,12 @@ class DumbDBMTestCase(unittest.TestCase):
         keys = self.keys_helper(f)
         f.close()
 
+    def test_write_contains(self):
+        f = dumbdbm.open(_fname)
+        f[b'1'] = b'hello'
+        assert b'1' in f
+        f.close()
+
     def test_write_write_read(self):
         # test for bug #482460
         f = dumbdbm.open(_fname)