diff --git a/examples/tfb/requirements.txt b/examples/tfb/requirements.txt
index 065eecbfc..aacf61adb 100644
--- a/examples/tfb/requirements.txt
+++ b/examples/tfb/requirements.txt
@@ -3,7 +3,7 @@ Automat==0.7.0
 colorama==0.4.1
 constantly==15.1.0
 greenlet==0.4.15
-gunicorn==19.9.0
+gunicorn==21.2.0
 hyperlink==18.0.0
 idna==2.8
 incremental==17.5.0