diff --git a/docs/requirements.txt b/docs/requirements.txt
index 0994ea9..1e10b04 100644
--- a/docs/requirements.txt
+++ b/docs/requirements.txt
@@ -1,5 +1,6 @@
 configparser
 networkx
+git+https://github.com/KarrLab/obj_model.git#egg=obj_model
 robpol86-sphinxcontrib-googleanalytics
 Sphinx
 sphinx_rtd_theme