diff --git a/docs/requirements.txt b/docs/requirements.txt
index 04bdf2fb..02652c62 100644
--- a/docs/requirements.txt
+++ b/docs/requirements.txt
@@ -6,3 +6,4 @@
 
 Sphinx>=1.7.5
 sphinx-rtd-theme>=0.4.0
+urllib3<2.0.0