diff --git a/src/main/asciidoc/models/design/catalog.puml b/src/main/asciidoc/models/design/catalog.puml
index e62c655..8ecfeab 100644
--- a/src/main/asciidoc/models/design/catalog.puml
+++ b/src/main/asciidoc/models/design/catalog.puml
@@ -23,7 +23,7 @@ package Salespoint {
         '+ addCategory(category : String) : boolean
         '+ removeCategory(category : String) : boolean
         + getName() : String
-        + getPrice() : @NonNull MonetaryAmount
+        + getPrice() : MonetaryAmount
         + setPrice(MonetaryAmount) : void
         '+ supports(quantity : Quantity) : boolean