diff --git a/docs/requirements.txt b/docs/requirements.txt
index c1f3f786afa1423075cce9f90ea11647d335c6ad..230a1bc81a61c054aab732cd1e749b343c8e3e1e 100644
--- a/docs/requirements.txt
+++ b/docs/requirements.txt
@@ -2,3 +2,4 @@ sphinx>=6
 pysolar==0.10.0
 docopt
 nbsphinx
+sphinx-rtd-theme==1.2.2
\ No newline at end of file