diff --git a/requirements.txt b/requirements.txt
index 36a32beb..50126c4c 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,3 +1,4 @@
+urllib3==1.26.15
 Sphinx==4.5.0
 sphinx-rtd-theme==1.0.0
 sphinx-autobuild==2021.3.14