diff --git a/src/collections/config/classes.ts b/src/collections/config/classes.ts
index fdf28501..7eff288c 100644
--- a/src/collections/config/classes.ts
+++ b/src/collections/config/classes.ts
@@ -148,7 +148,7 @@ export class MergeWithExisting {
   }
 
   static objectTTL(current: WeaviateObjectTTLConfig, update: ObjectTTLConfigUpdate): WeaviateObjectTTLConfig {
-    if (current === undefined) throw Error('Object TTL config is missing from the class schema.');
+    if (current === undefined) return update;
     return {
       enabled: update.enabled ?? current.enabled,
       deleteOn: update.deleteOn ?? current.deleteOn,
diff --git a/src/collections/config/utils.ts b/src/collections/config/utils.ts
index 9af0fe66..69ad19df 100644
--- a/src/collections/config/utils.ts
+++ b/src/collections/config/utils.ts
@@ -403,11 +403,16 @@ class ConfigMapping {
       return { enabled: false };
     }
     return {
+      ...v,
       enabled: v.enabled ?? false,
-      deleteOn: v.deleteOn,
+      deleteOn:
+        v.deleteOn == '_creationTimeUnix'
+          ? 'creationTime'
+          : v.deleteOn == '_lastUpdateTimeUnix'
+          ? 'updateTime'
+          : v.deleteOn,
       defaultTTLSeconds: v.defaultTtl,
       filterExpiredObjects: v.filterExpiredObjects,
-      ...v,
     };
   }
   static multiTenancy(v?: WeaviateMultiTenancyConfig): MultiTenancyConfig {
diff --git a/test/collections/config/integration.test.ts b/test/collections/config/integration.test.ts
index ecb16447..69964789 100644
--- a/test/collections/config/integration.test.ts
+++ b/test/collections/config/integration.test.ts
@@ -1095,7 +1095,7 @@ describe('Testing of the collection.config namespace', () => {
     const created = await collection.config.get();
     expect(created.objectTTL).toBeDefined();
     expect(created.objectTTL.enabled).toEqual(true);
-    expect(created.objectTTL.deleteOn).toEqual('_creationTimeUnix');
+    expect(created.objectTTL.deleteOn).toEqual('creationTime');
     expect(created.objectTTL.defaultTTLSeconds).toEqual(120);
 
     await collection.config.update({
@@ -1105,7 +1105,7 @@ describe('Testing of the collection.config namespace', () => {
     const updated = await collection.config.get();
     expect(updated.objectTTL).toBeDefined();
     expect(updated.objectTTL.enabled).toEqual(true);
-    expect(updated.objectTTL.deleteOn).toEqual('_lastUpdateTimeUnix');
+    expect(updated.objectTTL.deleteOn).toEqual('updateTime');
     expect(updated.objectTTL.defaultTTLSeconds).toEqual(400);
 
     await collection.config.update({