diff --git a/docs/conf.py b/docs/conf.py
index 2d4cf56d7..8160c3c7c 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -143,7 +143,7 @@
 ## -- Options for the edit_on_github extension ----------------------------------------
 
 if eval(setup_cfg.get('edit_on_github')):
-    extensions += ['astropy.sphinx.ext.edit_on_github']
+    extensions += ['astropy_helpers.sphinx.ext.edit_on_github']
 
     versionmod = __import__(setup_cfg['package_name'] + '.version')
     edit_on_github_project = setup_cfg['github_project']