diff --git a/rtd-requirements.txt b/rtd-requirements.txt
index 967d53a29..e806aa595 100644
--- a/rtd-requirements.txt
+++ b/rtd-requirements.txt
@@ -1,3 +1,3 @@
 -r requirements.txt
 jinja2
-sphinx>=1.3
+sphinx>=1.7.6