diff --git a/example.conf b/example.conf
index 96400a9..595b488 100644
--- a/example.conf
+++ b/example.conf
@@ -18,6 +18,12 @@ daemon = no
 ## Logging level, one of DEBUG, INFO, WARNING, ERROR, CRITICAL
 loglevel = DEBUG
 
+## If you use ssh-certificates with principals, you need this option
+## If commented, allowedPrincipals defaults to "git". At least, your certificates of the users
+## which want to use this repos, must have at least "git" as principal in their
+## certificates
+allowedPrincipals = git
+
 [group quux]
 members = jdoe wsmith @anothergroup
 writable = foo bar baz/thud