diff --git a/doc/Translate_ttl_to_spec.md b/doc/Translate_ttl_to_spec.md
index dc8dc54..80e61ae 100644
--- a/doc/Translate_ttl_to_spec.md
+++ b/doc/Translate_ttl_to_spec.md
@@ -85,10 +85,10 @@ as:id rdfs:domain [owl:unionOf (as:Link as:Object)]
 
 Maps to
 ```clojure
-(s/def ::Object (sh/map-spec (s/keys :opt-un [::id ...])))
+(s/def ::Object (sh/map-spec (s/keys :opt [::id ...])))
 
 
-(s/def ::Link (sh/map-spec (s/keys :opt-un [::id])))
+(s/def ::Link (sh/map-spec (s/keys :opt [::id])))
 ```
 
 ## **rdfs:subClassOf**