diff --git a/requirements-doc.txt b/requirements-doc.txt
index 0c31be7..f1632c4 100644
--- a/requirements-doc.txt
+++ b/requirements-doc.txt
@@ -1,5 +1,5 @@
 -r requirements.txt
 
 sphinx==1.6.7
-sphinx_rtd_theme
+sphinx_rtd_theme==0.2.4
 sphinx-autodoc-typehints==1.2.4