diff --git a/docs/requirements.txt b/docs/requirements.txt
index a77fbe3d..302f3223 100644
--- a/docs/requirements.txt
+++ b/docs/requirements.txt
@@ -2,4 +2,5 @@ Jinja2>=2.3
 Pygments>=1.2
 Sphinx>=1.3
 docutils>=0.7
-markupsafe
\ No newline at end of file
+markupsafe
+sphinxcontrib-httpdomain
\ No newline at end of file