diff --git a/sagemath.spec b/sagemath.spec
index 8a6a539..a296333 100644
--- a/sagemath.spec
+++ b/sagemath.spec
@@ -288,6 +288,7 @@ BuildRequires:	python-flask-silk
 BuildRequires:	python-ipython
 BuildRequires:	python-matplotlib
 BuildRequires:	python-networkx
+BuildRequires:	python-sphinx
 BuildRequires:	python-twisted-web
 BuildRequires:	python-twisted-web2
 BuildRequires:	polybori-devel