diff --git a/CHANGES.rst b/CHANGES.rst
index 2d064a1..08bd401 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -35,3 +35,6 @@
   be registered locally with ``z3c.baseregistry`` (previously they
   were always registered in the global site manager).
   See https://github.com/NextThought/nti.externalization/issues/28
+- Drop dependency on ``zope.preference``. It was not used by this
+  package, although our ``configure.zcml`` did include it. If you use
+  ``zope.preference``, please include it in your own ZCML file.
diff --git a/setup.py b/setup.py
index d7d3b1f..2ede5f7 100755
--- a/setup.py
+++ b/setup.py
@@ -73,8 +73,7 @@ def _read(fname):
         'zope.intid',
         'zope.lifecycleevent',
         'zope.location',
-        'zope.mimetype',
-        'zope.preference',
+        'zope.mimetype >= 2.3.0',
         'zope.proxy',
         'zope.schema',
         'zope.security',
diff --git a/src/nti/externalization/configure.zcml b/src/nti/externalization/configure.zcml
index 589d95c..39ce157 100644
--- a/src/nti/externalization/configure.zcml
+++ b/src/nti/externalization/configure.zcml
@@ -10,9 +10,6 @@
 
 	<include package="zope.annotation" />
 
-	<include package="zope.preference" file="meta.zcml" />
-	<include package="zope.preference" />
-
 	<subscriber	provides=".interfaces.IExternalMappingDecorator"
 				for="zope.dublincore.interfaces.IDCExtended"
 				factory=".dublincore.DCExtendedExternalMappingDecorator" />