diff --git a/docs/requirements.txt b/docs/requirements.txt
index a4101214..2126bd66 100644
--- a/docs/requirements.txt
+++ b/docs/requirements.txt
@@ -1 +1,2 @@
-openflexure-microscope==1.0.0b0
\ No newline at end of file
+openflexure-microscope==1.0.0b0
+sphinxcontrib.httpdomain
\ No newline at end of file