diff --git a/pkg/service/submissions.go b/pkg/service/submissions.go
index 22f44cc..7955131 100644
--- a/pkg/service/submissions.go
+++ b/pkg/service/submissions.go
@@ -127,7 +127,7 @@ func (svc *Service) SetSubmissionCompleted(ctx context.Context, params api.SetSu
 	return err
 }
 
-// PatchSubmissionModel implements patchSubmissionModel operation.
+// UpdateSubmissionModel implements patchSubmissionModel operation.
 //
 // Update model following role restrictions.
 //
diff --git a/pkg/service_internal/submissions.go b/pkg/service_internal/submissions.go
index 491939d..8e46735 100644
--- a/pkg/service_internal/submissions.go
+++ b/pkg/service_internal/submissions.go
@@ -8,6 +8,21 @@ import (
 	"git.itzana.me/strafesnet/maps-service/pkg/model"
 )
 
+// UpdateSubmissionModel implements patchSubmissionModel operation.
+//
+// Update model following role restrictions.
+//
+// POST /submissions/{SubmissionID}/model
+func (svc *Service) UpdateSubmissionModel(ctx context.Context, params internal.UpdateSubmissionModelParams) error {
+	// check if Status is ChangesRequested|Submitted|UnderConstruction
+	pmap := datastore.Optional()
+	pmap.AddNotNil("asset_id", params.ModelID)
+	pmap.AddNotNil("asset_version", params.VersionID)
+	//always reset completed when model changes
+	pmap.Add("completed", false)
+	return svc.DB.Submissions().IfStatusThenUpdate(ctx, params.SubmissionID, []model.Status{model.StatusValidating}, pmap)
+}
+
 // ActionSubmissionValidate invokes actionSubmissionValidate operation.
 //
 // Role Validator changes status from Validating -> Validated.