diff --git a/doc/requirements.txt b/doc/requirements.txt
index 71289f8..7799087 100644
--- a/doc/requirements.txt
+++ b/doc/requirements.txt
@@ -1,3 +1,4 @@
 exhale
 breathe
-sphinx>=2.1.2
\ No newline at end of file
+sphinx>=2.1.2
+sphinx-rtd-theme