diff --git a/evennia/commands/cmdset.py b/evennia/commands/cmdset.py
index 996672213b..49a2875727 100644
--- a/evennia/commands/cmdset.py
+++ b/evennia/commands/cmdset.py
@@ -391,11 +391,11 @@ class CmdSet(with_metaclass(_CmdSetMeta, object)):
                 cmdset_c = self._union(cmdset_a, self)
 
             # pass through options whenever they are set, unless the merging or higher-prio
-            # set changes the setting (i.e. has a non-None value).
+            # set changes the setting (i.e. has a non-None value). We don't pass through
+            # the duplicates setting; that is per-merge
             cmdset_c.no_channels = self.no_channels if cmdset_a.no_channels is None else cmdset_a.no_channels
             cmdset_c.no_exits = self.no_exits if cmdset_a.no_exits is None else cmdset_a.no_exits
             cmdset_c.no_objs = self.no_objs if cmdset_a.no_objs is None else cmdset_a.no_objs
-            cmdset_c.duplicates = self.duplicates if cmdset_a.duplicates is None else cmdset_a.duplicates
 
         else:
             # B higher priority than A
@@ -415,11 +415,11 @@ class CmdSet(with_metaclass(_CmdSetMeta, object)):
                 cmdset_c = self._union(self, cmdset_a)
 
             # pass through options whenever they are set, unless the higher-prio
-            # set changes the setting (i.e. has a non-None value).
+            # set changes the setting (i.e. has a non-None value). We don't pass through
+            # the duplicates setting; that is per-merge
             cmdset_c.no_channels = cmdset_a.no_channels if self.no_channels is None else self.no_channels
             cmdset_c.no_exits = cmdset_a.no_exits if self.no_exits is None else self.no_exits
             cmdset_c.no_objs = cmdset_a.no_objs if self.no_objs is None else self.no_objs
-            cmdset_c.duplicates = cmdset_a.duplicates if self.duplicates is None else self.duplicates
 
         # we store actual_mergetype since key_mergetypes
         # might be different from the main mergetype.
diff --git a/evennia/commands/tests.py b/evennia/commands/tests.py
index c238b7e3dd..d4ad6bc93a 100644
--- a/evennia/commands/tests.py
+++ b/evennia/commands/tests.py
@@ -186,7 +186,7 @@ class TestCmdSetMergers(TestCase):
         self.assertTrue(cmdset_f.no_exits)
         self.assertTrue(cmdset_f.no_objs)
         self.assertTrue(cmdset_f.no_channels)
-        self.assertTrue(cmdset_f.duplicates)
+        self.assertFalse(cmdset_f.duplicates)
         self.assertEqual(len(cmdset_f.commands), 4)
         a.priority = 2
         b.priority = 1
@@ -198,7 +198,7 @@ class TestCmdSetMergers(TestCase):
         self.assertTrue(cmdset_f.no_channels)
         self.assertTrue(cmdset_f.duplicates)
         self.assertEqual(len(cmdset_f.commands), 4)
-        cmdset_f = a + b + c + d # forward, A top priority
+        cmdset_f = a + b + c + d # forward, A top priority. This never happens in practice.
         self.assertTrue(cmdset_f.no_exits)
         self.assertTrue(cmdset_f.no_objs)
         self.assertTrue(cmdset_f.no_channels)
@@ -208,17 +208,17 @@ class TestCmdSetMergers(TestCase):
         b.priority = 0
         c.priority = 1
         d.priority = 2
-        cmdset_f = d + c + b + a # reverse, A low prio
+        cmdset_f = d + c + b + a # reverse, A low prio. This never happens in practice.
         self.assertTrue(cmdset_f.no_exits)
         self.assertTrue(cmdset_f.no_objs)
         self.assertTrue(cmdset_f.no_channels)
-        self.assertTrue(cmdset_f.duplicates)
+        self.assertFalse(cmdset_f.duplicates)
         self.assertEqual(len(cmdset_f.commands), 4)
         cmdset_f = a + b + c + d # forward, A low prio
         self.assertTrue(cmdset_f.no_exits)
         self.assertTrue(cmdset_f.no_objs)
         self.assertTrue(cmdset_f.no_channels)
-        self.assertTrue(cmdset_f.duplicates)
+        self.assertFalse(cmdset_f.duplicates)
         self.assertEqual(len(cmdset_f.commands), 4)
         c.no_exits = False
         b.no_objs = False
@@ -322,6 +322,18 @@ class TestGetAndMergeCmdSets(TwistedTestCase, EvenniaTest):
         deferred.addCallback(_callback)
         return deferred
 
+    def test_duplicates(self):
+        a, b, c, d = self.cmdset_a, self.cmdset_b, self.cmdset_c, self.cmdset_d
+        a.no_exits = True
+        a.no_channels = True
+        b.duplicates = True
+        d.duplicates = True
+        self.set_cmdsets(self.obj1, a, b, c, d)
+        deferred = cmdhandler.get_and_merge_cmdsets(self.obj1, None, None, self.obj1, "object")
+        def _callback(cmdset):
+            self.assertEqual(len(cmdset.commands), 9)
+        deferred.addCallback(_callback)
+        return deferred