diff --git a/tools/AccountSynchronizer/accountSynchronizer/resources/config.properties b/tools/AccountSynchronizer/accountSynchronizer/resources/config.properties
index 6d000a683216ae625a1bf618799abe3ab3667bda..98b0804086c28e73aacf21719b531c75134a624f 100644
--- a/tools/AccountSynchronizer/accountSynchronizer/resources/config.properties
+++ b/tools/AccountSynchronizer/accountSynchronizer/resources/config.properties
@@ -15,3 +15,6 @@ dm.database.connection = jdbc:postgresql://127.0.0.1:11136/dm
 dm.database.username = dm
 ### dm.database.password = 
 
+# The user name prefix that gets append to every badge number.
+user.userid.prefix = d
+