diff --git a/vorgang-manager-server/src/main/java/de/ozgcloud/vorgang/collaboration/CollaborationRequestMapper.java b/vorgang-manager-server/src/main/java/de/ozgcloud/vorgang/collaboration/CollaborationRequestMapper.java
index 7158875aeee297eb2c083b8ae35d5d20aaa80fd6..669c10135e95e316b8ded21463b24e5dbee82726 100644
--- a/vorgang-manager-server/src/main/java/de/ozgcloud/vorgang/collaboration/CollaborationRequestMapper.java
+++ b/vorgang-manager-server/src/main/java/de/ozgcloud/vorgang/collaboration/CollaborationRequestMapper.java
@@ -24,10 +24,11 @@
 package de.ozgcloud.vorgang.collaboration;
 
 import org.mapstruct.Mapper;
+import org.mapstruct.ReportingPolicy;
 
 import de.ozgcloud.vorgang.vorgang.GrpcCollaborationRequest;
 
-@Mapper
+@Mapper(unmappedTargetPolicy = ReportingPolicy.WARN)
 public interface CollaborationRequestMapper {
 
 	CollaborationRequest mapFrom(GrpcCollaborationRequest grpcCollaborationRequest);