diff --git a/test/collection/test_config.py b/test/collection/test_config.py
index 360a0d138..fa02a918e 100644
--- a/test/collection/test_config.py
+++ b/test/collection/test_config.py
@@ -14,6 +14,7 @@
     Vectorizers,
     _AsyncReplicationConfig,
     _CollectionConfigCreate,
+    _CollectionConfigUpdate,
     _GenerativeProvider,
     _ReplicationConfig,
     _ReplicationConfigUpdate,
@@ -30,6 +31,7 @@
     VectorDistances,
 )
 from weaviate.collections.classes.config_vectors import _VectorConfigCreate
+from weaviate.collections.classes.config_object_ttl import ObjectTTLConfigUpdate
 from weaviate.exceptions import WeaviateInsertInvalidPropertyError
 
 DEFAULTS = {
@@ -3529,3 +3531,23 @@ def test_reconfigure_inverted_index_without_stopword_presets_leaves_existing(sel
         }
         merged = rc.merge_with_existing(existing)
         assert merged["stopwordPresets"] == {"fr": ["le", "la"]}
+
+
+def test_object_ttl_update_uses_server_schema_key():
+    stored = {
+        "objectTtlConfig": {
+            "enabled": True,
+            "deleteOn": "expiresAt",
+            "defaultTtl": 3600,
+            "filterExpiredObjects": False,
+        }
+    }
+    update = _CollectionConfigUpdate(
+        object_ttl_config=ObjectTTLConfigUpdate(enabled=True, filterExpiredObjects=True)
+    )
+    merged = update.merge_with_existing(stored)
+
+    assert "objectTTLConfig" not in merged
+    assert merged["objectTtlConfig"]["filterExpiredObjects"] is True
+    assert merged["objectTtlConfig"]["defaultTtl"] == 3600
+    assert merged["objectTtlConfig"]["deleteOn"] == "expiresAt"
diff --git a/weaviate/collections/classes/config.py b/weaviate/collections/classes/config.py
index 390578756..7b088ae72 100644
--- a/weaviate/collections/classes/config.py
+++ b/weaviate/collections/classes/config.py
@@ -1616,7 +1616,7 @@ class _CollectionConfigUpdate(_ConfigUpdateModel):
     invertedIndexConfig: Optional[InvertedIndexConfigUpdate] = Field(
         default=None, alias="inverted_index_config"
     )
-    objectTTLConfig: Optional[ObjectTTLConfigUpdate] = Field(
+    objectTtlConfig: Optional[ObjectTTLConfigUpdate] = Field(
         default=None, alias="object_ttl_config"
     )
     replicationConfig: Optional[ReplicationConfigUpdate] = Field(
@@ -1745,10 +1745,11 @@ def merge_with_existing(self, schema: Dict[str, Any]) -> Dict[str, Any]:
             schema["multiTenancyConfig"] = self.multiTenancyConfig.merge_with_existing(
                 schema["multiTenancyConfig"]
             )
-        if self.objectTTLConfig is not None:
-            schema["objectTTLConfig"] = self.objectTTLConfig.merge_with_existing(
-                schema.get("objectTTLConfig", {})
+        if self.objectTtlConfig is not None:
+            schema["objectTtlConfig"] = self.objectTtlConfig.merge_with_existing(
+                schema.get("objectTtlConfig") or schema.get("objectTTLConfig") or {}
             )
+            schema.pop("objectTTLConfig", None)
         if self.vectorIndexConfig is not None:
             self.__check_quantizers(self.vectorIndexConfig.quantizer, schema["vectorIndexConfig"])
             schema["vectorIndexConfig"] = self.vectorIndexConfig.merge_with_existing(