diff --git a/ca.conf.sample b/ca.conf.sample
index 1a7db2e..d81a8e9 100644
--- a/ca.conf.sample
+++ b/ca.conf.sample
@@ -7,7 +7,7 @@
         "validity-period": "360",
         "ca-info": "NDN Testbed CA",
 
-        "probe": "Use the university/organization name as input",
+        "probe": "email",
 
         "targeted-list": "Use your email address (edu preferred) as input",
         "related-ca-list":