diff --git a/intro-cmx/cmx-04-mission/requirements.txt b/intro-cmx/cmx-04-mission/requirements.txt
index 52faa1eca..162e5e3d6 100644
--- a/intro-cmx/cmx-04-mission/requirements.txt
+++ b/intro-cmx/cmx-04-mission/requirements.txt
@@ -1,4 +1,4 @@
 webexteamsapi
 requests==2.18.4
 requests-toolbelt==0.8.0
-Flask==0.12.2
+Flask==1.0