diff --git a/requirements-docs.txt b/requirements-docs.txt
index b3a24b5ec..43ca36270 100644
--- a/requirements-docs.txt
+++ b/requirements-docs.txt
@@ -2,3 +2,4 @@ Sphinx>=1.3.1,!=1.7.1
 sphinx-rtd-theme
 sphinx-intl
 sphinx-reredirects
+pyyaml