diff --git a/org.eclipse.lyo.oslc4j.codegenerator/src/org/eclipse/lyo/oslc4j/codegenerator/main/generateSpecification.mtl b/org.eclipse.lyo.oslc4j.codegenerator/src/org/eclipse/lyo/oslc4j/codegenerator/main/generateSpecification.mtl
index edcecb6..658bb15 100644
--- a/org.eclipse.lyo.oslc4j.codegenerator/src/org/eclipse/lyo/oslc4j/codegenerator/main/generateSpecification.mtl
+++ b/org.eclipse.lyo.oslc4j.codegenerator/src/org/eclipse/lyo/oslc4j/codegenerator/main/generateSpecification.mtl
@@ -46,7 +46,9 @@
 /]
 
 [query public relevantDomainSpecifications(aSpecification : Specification) : Set(DomainSpecification) =
-relevantResources(aSpecification)->collectNested(aResource : Resource | aResource.definingDomainSpecification())->flatten()->asSet()
+aSpecification.domainSpecifications->union(
+    relevantResources(aSpecification)->collectNested(aResource : Resource | aResource.definingDomainSpecification())->flatten()->asSet()
+)
 /]
 
 [query public relevantVocabularies(aSpecification : Specification) : Set(Vocabulary) =