diff --git a/sphinx/requirements.txt b/sphinx/requirements.txt
index 79bab6c..5bf8fe0 100644
--- a/sphinx/requirements.txt
+++ b/sphinx/requirements.txt
@@ -5,7 +5,7 @@ chardet==3.0.4
 colorama==0.4.1
 docutils==0.14
 funcsigs==1.0.2
-idna==2.8
+idna==3.7
 imagesize==1.1.0
 Jinja2==2.11.3
 MarkupSafe==1.1.0