diff --git a/setup.py b/setup.py
index b7697dbd3..80050a2c9 100644
--- a/setup.py
+++ b/setup.py
@@ -76,7 +76,8 @@ dev_extras = [
 
 docs_extras = [
     'repoze.sphinx.autointerface',
-    'Sphinx>=1.0',  # autodoc_member_order = 'bysource', autodoc_default_flags
+    # autodoc_member_order = 'bysource', autodoc_default_flags, and #4686
+    'Sphinx >=1.0,<=1.5.6',
     'sphinx_rtd_theme',
 ]