diff --git a/Lib/bsddb/dbshelve.py b/Lib/bsddb/dbshelve.py
index 3727270..7344945 100644
--- a/Lib/bsddb/dbshelve.py
+++ b/Lib/bsddb/dbshelve.py
@@ -135,7 +135,7 @@
 
 
     def keys(self, txn=None):
-        if txn != None:
+        if txn is not None:
             return self.db.keys(txn)
         else:
             return self.db.keys()
@@ -161,7 +161,7 @@
 
 
     def items(self, txn=None):
-        if txn != None:
+        if txn is not None:
             items = self.db.items(txn)
         else:
             items = self.db.items()
@@ -172,7 +172,7 @@
         return newitems
 
     def values(self, txn=None):
-        if txn != None:
+        if txn is not None:
             values = self.db.values(txn)
         else:
             values = self.db.values()
diff --git a/Lib/bsddb/test/test_basics.py b/Lib/bsddb/test/test_basics.py
index 4e070bd..6b99cc1 100644
--- a/Lib/bsddb/test/test_basics.py
+++ b/Lib/bsddb/test/test_basics.py
@@ -366,7 +366,7 @@
         else:
             if set_raises_error:
                 self.fail("expected exception")
-            if n != None:
+            if n is not None:
                 self.fail("expected None: %r" % (n,))
 
         rec = c.get_both(b'0404', self.makeData(b'0404'))
@@ -380,7 +380,7 @@
         else:
             if get_raises_error:
                 self.fail("expected exception")
-            if n != None:
+            if n is not None:
                 self.fail("expected None: %r" % (n,))
 
         if self.d.get_type() == db.DB_BTREE:
diff --git a/Lib/bsddb/test/test_dbtables.py b/Lib/bsddb/test/test_dbtables.py
index 8964de8..f1328f0 100644
--- a/Lib/bsddb/test/test_dbtables.py
+++ b/Lib/bsddb/test/test_dbtables.py
@@ -328,7 +328,7 @@
         self.tdb.Insert(tabname, {'Type': b'Unknown', 'Access': b'0'})
 
         def set_type(type):
-            if type == None:
+            if type is None:
                 return b'MP3'
             return type