diff -r 6f6c87888b22 -r 8fb5212652ec hgdemandimport/demandimportpy3.py
--- a/hgdemandimport/demandimportpy3.py	Tue Aug 15 10:15:31 2017 -0700
+++ b/hgdemandimport/demandimportpy3.py	Fri Aug 18 11:08:17 2017 -0700
@@ -27,7 +27,6 @@
 from __future__ import absolute_import
 
 import contextlib
-import os
 import sys
 
 import importlib.abc
@@ -81,8 +80,7 @@
         pass
 
 def enable():
-    if os.environ.get('HGDEMANDIMPORT') != 'disable':
-        sys.path_hooks.insert(0, _makefinder)
+    sys.path_hooks.insert(0, _makefinder)
 
 @contextlib.contextmanager
 def deactivated():