1 files changed, 1 insertions, 2 deletions
diff --git a/setup.py b/setup.py
index 7ac766c8c2..ae86e6c9fb 100644
--- a/setup.py
+++ b/setup.py
@@ -289,8 +289,7 @@ if not PY3:
   INSTALL_REQUIRES += ('futures>=2.2.0', 'enum34>=1.0.4')
 
 SETUP_REQUIRES = INSTALL_REQUIRES + (
-    'sphinx>=1.3',
-    'sphinx_rtd_theme>=0.1.8',
+    'Sphinx~=1.8.1',
     'six>=1.10',
   ) if ENABLE_DOCUMENTATION_BUILD else ()