diff --git a/python-pygit2.spec b/python-pygit2.spec
index 844212e..f01b6b3 100644
--- a/python-pygit2.spec
+++ b/python-pygit2.spec
@@ -37,6 +37,7 @@ The python3-%{pkgname} package contains the Python 3 bindings.
 Summary:        Documentation for %{name}
 BuildArch:      noarch
 BuildRequires:  /usr/bin/sphinx-build
+BuildRequires:  python3-sphinx_rtd_theme
 
 %description    doc
 Documentation for %{name}.