--- a/astropy_helpers/commands/build_sphinx.py	2018-06-01 10:01:50.000000000 +0800
+++ b/astropy_helpers/commands/build_sphinx.py	2018-06-19 11:44:47.802647397 +0800
@@ -126,7 +126,7 @@
         build_cmd = self.get_finalized_command('build')
         build_cmd_path = os.path.abspath(build_cmd.build_lib)
 
-        ah_importer = pkgutil.get_importer('astropy_helpers')
+        ah_importer = pkgutil.get_importer('/usr/lib/python2.7/site-packages/astropy_helpers')
         if ah_importer is None:
             ah_path = '.'
         else: