diff --git a/lib/model/query/submissions.js b/lib/model/query/submissions.js
index a5f66827e..7379b0b2e 100644
--- a/lib/model/query/submissions.js
+++ b/lib/model/query/submissions.js
@@ -163,7 +163,10 @@ order by path asc, value asc`)
 
 // Helper function to assign submission.currentVersionSubmitter to submission.currentVersion.submitter
 // Current there is no way to create such complex object using `extender` and `unjoiner` framework functions
-const assignCurrentVersionSubmitter = (x) => x.withAux('currentVersion', x.aux.currentVersion.withAux('submitter', x.aux.currentVersionSubmitter));
+//
+// New instance of Submission is created to remove all aux objects from it (except submitter).
+// If those aux's are kept then properties of aux are merged at the root level cb#858
+const assignCurrentVersionSubmitter = (x) => (new Submission(x, { submitter: x.aux.submitter })).withAux('currentVersion', x.aux.currentVersion.withAux('submitter', x.aux.currentVersionSubmitter));
 
 const _get = extender(Submission, Submission.Def.into('currentVersion'))(Actor.into('submitter'), Actor.alias('current_version_actors', 'currentVersionSubmitter'))((fields, extend, options, projectId, xmlFormId, draft) => sql`
   select ${fields} from 
diff --git a/test/integration/api/submissions.js b/test/integration/api/submissions.js
index d8f50e5ef..c1c765d99 100644
--- a/test/integration/api/submissions.js
+++ b/test/integration/api/submissions.js
@@ -3183,6 +3183,48 @@ one,h,/data/h,2000-01-01T00:06,2000-01-01T00:07,-5,-6,,ee,ff
               body.submitter.displayName.should.equal('Alice');
             })))));
 
+    // cb#858
+    it('should not mince object properties', testService(async (service, container) => {
+      const asAlice = await service.login('alice');
+      const asBob = await service.login('bob');
+
+      await asAlice.post('/v1/projects/1/forms/simple/submissions')
+        .send(testData.instances.simple.one)
+        .set('Content-Type', 'text/xml')
+        .expect(200);
+
+      await asBob.put('/v1/projects/1/forms/simple/submissions/one')
+        .set('Content-Type', 'text/xml')
+        .send(withSimpleIds('one', 'two'))
+        .expect(200);
+
+      await container.run(sql`UPDATE actors SET "createdAt" = '2020-01-01' WHERE "displayName" = 'Alice'`);
+      await container.run(sql`UPDATE actors SET "createdAt" = '2021-01-01' WHERE "displayName" = 'Bob'`);
+
+      await container.run(sql`UPDATE submissions SET "createdAt" = '2022-01-01', "updatedAt" = '2023-01-01'`);
+
+      await container.run(sql`UPDATE submission_defs SET "createdAt" = '2022-01-01' WHERE "instanceId" = 'one'`);
+      await container.run(sql`UPDATE submission_defs SET "createdAt" = '2023-01-01' WHERE "instanceId" = 'two'`);
+
+      await asAlice.get('/v1/projects/1/forms/simple/submissions/one')
+        .set('X-Extended-Metadata', 'true')
+        .expect(200)
+        .then(({ body }) => {
+          body.should.be.an.ExtendedSubmission();
+
+          body.createdAt.should.match(/2022/);
+          body.updatedAt.should.match(/2023/);
+
+          body.submitter.displayName.should.equal('Alice');
+          body.submitter.createdAt.should.match(/2020/);
+
+          body.currentVersion.createdAt.should.match(/2023/);
+
+          body.currentVersion.submitter.displayName.should.equal('Bob');
+          body.currentVersion.submitter.createdAt.should.match(/2021/);
+        });
+    }));
+
     it('should redirect to the version if the referenced instanceID is out of date', testService((service) =>
       service.login('alice', (asAlice) =>
         asAlice.post('/v1/projects/1/submission')