diff --git a/doc/requirements.txt b/doc/requirements.txt
index 6da433c..9d17e6b 100644
--- a/doc/requirements.txt
+++ b/doc/requirements.txt
@@ -13,7 +13,7 @@ livereload==2.5.1
 MarkupSafe==1.0
 pathtools==0.1.2
 port-for==0.3.1
-Pygments==2.2.0
+Pygments==2.7.4
 pytz==2017.3
 PyYAML==3.12
 recommonmark==0.4.0