diff --git a/doc/changes/DM-53791.bugfix.md b/doc/changes/DM-53791.bugfix.md
new file mode 100644
index 0000000..a93233a
--- /dev/null
+++ b/doc/changes/DM-53791.bugfix.md
@@ -0,0 +1 @@
+Fix copying of `ConfigChoiceField` and `RegistryField`.
diff --git a/python/lsst/pex/config/configChoiceField.py b/python/lsst/pex/config/configChoiceField.py
index b96f66c..412c5b6 100644
--- a/python/lsst/pex/config/configChoiceField.py
+++ b/python/lsst/pex/config/configChoiceField.py
@@ -192,7 +192,7 @@ def _copy(self, config: Config) -> ConfigInstanceDict:
         result._typemap = self._typemap
         if self._selection is not None:
             if self._field.multi:
-                result._selection = SelectionSet(result._dict, self._selection._set)
+                result._selection = SelectionSet(self, self._selection._set)
             else:
                 result._selection = self._selection
         return result
diff --git a/tests/test_configChoiceField.py b/tests/test_configChoiceField.py
index f2fbf7c..7114763 100644
--- a/tests/test_configChoiceField.py
+++ b/tests/test_configChoiceField.py
@@ -165,6 +165,20 @@ def testNoPickle(self):
         with self.assertRaises(pexConfig.UnexpectedProxyUsageError):
             pickle.dumps(self.config.c.names)
 
+    def test_copy(self):
+        """Test the copy method on a ConfigChoiceField."""
+        copy1: Config3 = self.config.copy()
+        copy1.a["AAA"].f = 1
+        copy1.a["BBB"].f = 1.0
+        copy1.a = "BBB"
+        self.assertEqual(self.config.a.name, "AAA")
+        self.assertEqual(self.config.a.active.f, 4)
+        self.assertEqual(self.config.a["AAA"].f, 4)
+        self.assertEqual(self.config.a["BBB"].f, 0.5)
+        self.assertEqual(copy1.a.name, "BBB")
+        self.assertEqual(copy1.a["AAA"].f, 1)
+        self.assertEqual(copy1.a["BBB"].f, 1.0)
+
 
 if __name__ == "__main__":
     unittest.main()