diff --git a/data/schema/SCHEMA-SCHEMA b/data/schema/SCHEMA-SCHEMA
index 593449bab..72a4e9b09 100644
--- a/data/schema/SCHEMA-SCHEMA
+++ b/data/schema/SCHEMA-SCHEMA
@@ -12,7 +12,6 @@ key:                source   required  single      lookup=dn42.registry
 mnt-by:             DN42-MNT
 source:             DN42
 remarks:            # option descriptions
-source:             DN42
                     Attribute names must match /[a-zA-Z]([a-zA-Z0-9_\-]*[a-zA-Z0-9])?/.
 +
                     required