diff --git a/examples/tfb/requirements.txt b/examples/tfb/requirements.txt
index 065eecbfc..cd974be7c 100644
--- a/examples/tfb/requirements.txt
+++ b/examples/tfb/requirements.txt
@@ -5,7 +5,7 @@ constantly==15.1.0
 greenlet==0.4.15
 gunicorn==19.9.0
 hyperlink==18.0.0
-idna==2.8
+idna==3.15
 incremental==17.5.0
 lxml==4.3.1
 meinheld==0.6.1