diff --git a/integration/test_collection_config.py b/integration/test_collection_config.py
index 3a7d5b428..f8ab40e3c 100644
--- a/integration/test_collection_config.py
+++ b/integration/test_collection_config.py
@@ -1655,3 +1655,119 @@ def test_uncompressed_quantitizer(collection_factory: CollectionFactory) -> None
     assert config.vector_index_config is not None
     assert isinstance(config.vector_index_config, _VectorIndexConfigHNSW)
     assert config.vector_index_config.quantizer is None
+
+
+def test_quantitizer_update(collection_factory: CollectionFactory) -> None:
+    dummy = collection_factory("dummy", ports=(8090, 50061))
+    if dummy._connection._weaviate_version.is_lower_than(1, 33, 0):
+        pytest.skip("uncompressed is not supported in Weaviate versions lower than 1.33.0")
+
+    collection = collection_factory(
+        vector_config=[
+            Configure.Vectors.self_provided(
+                name="hnsw",
+                vector_index_config=wvc.config.Configure.VectorIndex.hnsw(
+                    quantizer=Configure.VectorIndex.Quantizer.none()
+                ),
+            ),
+            Configure.Vectors.self_provided(
+                name="flat",
+                vector_index_config=wvc.config.Configure.VectorIndex.flat(
+                    quantizer=Configure.VectorIndex.Quantizer.none()
+                ),
+            ),
+            Configure.Vectors.self_provided(
+                name="dynamic",
+                vector_index_config=wvc.config.Configure.VectorIndex.dynamic(
+                    flat=Configure.VectorIndex.flat(
+                        quantizer=Configure.VectorIndex.Quantizer.none()
+                    ),
+                    hnsw=Configure.VectorIndex.hnsw(
+                        quantizer=Configure.VectorIndex.Quantizer.none()
+                    ),
+                ),
+            ),
+        ],
+        ports=(8090, 50061),  # async
+    )
+
+    collection.config.update_quantizer(
+        name="hnsw", hnsw_quantizer=Reconfigure.VectorIndex.Quantizer.pq()
+    )
+
+    config = collection.config.get()
+    assert config.vector_config is not None
+    hnsw_config = config.vector_config["hnsw"].vector_index_config
+    assert hnsw_config is not None
+    assert isinstance(hnsw_config, _VectorIndexConfigHNSW)
+    assert hnsw_config.quantizer is not None
+    assert isinstance(hnsw_config.quantizer, _PQConfig)
+
+    # other indices are not changed
+    flat_config = config.vector_config["flat"].vector_index_config
+    assert flat_config is not None
+    assert isinstance(flat_config, _VectorIndexConfigFlat)
+    assert flat_config.quantizer is None
+
+    dynamic_config = config.vector_config["dynamic"].vector_index_config
+    assert dynamic_config is not None
+    assert isinstance(dynamic_config, _VectorIndexConfigDynamic)
+    assert dynamic_config.hnsw.quantizer is None
+    assert dynamic_config.flat.quantizer is None
+
+    # collection.config.update_quantizer(
+    #     name="flat",
+    #     flat_quantizer=Reconfigure.VectorIndex.Quantizer.bq()
+    # )
+
+    # collection.config.update(
+    #     vector_config=wvc.config.Reconfigure.Vectors.update(
+    #         name="flat",
+    #         vector_index_config=Reconfigure.VectorIndex.flat(quantizer=Reconfigure.VectorIndex.Quantizer.bq())
+    #     )
+    # )
+
+    # config = collection.config.get()
+    # assert config.vector_config is not None
+    # flat_config = config.vector_config["flat"].vector_index_config
+    # assert flat_config is not None
+    # assert isinstance(flat_config, _VectorIndexConfigFlat)
+    # assert flat_config.quantizer is not None
+    # assert isinstance(flat_config.quantizer, _BQConfig)
+
+    collection.config.update_quantizer(
+        name="dynamic",
+        hnsw_quantizer=Reconfigure.VectorIndex.Quantizer.sq(),
+        # flat_quantizer=Reconfigure.VectorIndex.Quantizer.pq()
+    )
+
+    config = collection.config.get()
+    assert config.vector_config is not None
+    dynamic_config = config.vector_config["dynamic"].vector_index_config
+    assert dynamic_config is not None
+    assert isinstance(dynamic_config, _VectorIndexConfigDynamic)
+    assert dynamic_config.hnsw.quantizer is not None
+    assert isinstance(dynamic_config.hnsw.quantizer, _SQConfig)
+    assert dynamic_config.flat.quantizer is None
+
+
+def test_quantitizer_update_legacy(collection_factory: CollectionFactory) -> None:
+    dummy = collection_factory("dummy", ports=(8090, 50061))
+    if dummy._connection._weaviate_version.is_lower_than(1, 33, 0):
+        pytest.skip("uncompressed is not supported in Weaviate versions lower than 1.33.0")
+
+    collection = collection_factory(
+        vectorizer_config=Configure.Vectorizer.none(),
+        vector_index_config=wvc.config.Configure.VectorIndex.dynamic(
+            flat=Configure.VectorIndex.flat(quantizer=Configure.VectorIndex.Quantizer.none()),
+            hnsw=Configure.VectorIndex.hnsw(quantizer=Configure.VectorIndex.Quantizer.none()),
+        ),
+        ports=(8090, 50061),  # async
+    )
+
+    collection.config.update_quantizer(hnsw_quantizer=Reconfigure.VectorIndex.Quantizer.pq())
+    config = collection.config.get()
+    assert config.vector_index_config is not None
+    assert isinstance(config.vector_index_config, _VectorIndexConfigDynamic)
+    assert config.vector_index_config.hnsw.quantizer is not None
+    assert isinstance(config.vector_index_config.hnsw.quantizer, _PQConfig)
diff --git a/weaviate/collections/classes/config.py b/weaviate/collections/classes/config.py
index c30c9967e..c4ae85667 100644
--- a/weaviate/collections/classes/config.py
+++ b/weaviate/collections/classes/config.py
@@ -1128,6 +1128,29 @@ def mutual_exclusivity(
             )
         return v
 
+    def __check_vectorizer_quantizer(
+        self, vectorIndexConfig: _VectorIndexConfigUpdate, vector_index_config: dict
+    ) -> None:
+        if isinstance(vectorIndexConfig, _VectorIndexConfigHNSWUpdate) or isinstance(
+            vectorIndexConfig, _VectorIndexConfigFlatUpdate
+        ):
+            self.__check_quantizers(
+                vectorIndexConfig.quantizer,
+                vector_index_config,
+            )
+        else:
+            assert isinstance(vectorIndexConfig, _VectorIndexConfigDynamicUpdate)
+            if vectorIndexConfig.hnsw is not None:
+                self.__check_quantizers(
+                    vectorIndexConfig.hnsw.quantizer,
+                    vector_index_config,
+                )
+            if vectorIndexConfig.flat is not None:
+                self.__check_quantizers(
+                    vectorIndexConfig.flat.quantizer,
+                    vector_index_config,
+                )
+
     def __check_quantizers(
         self,
         quantizer: Optional[_QuantizerConfigUpdate],
@@ -1145,7 +1168,7 @@ def __check_quantizers(
             or (
                 isinstance(quantizer, _BQConfigUpdate)
                 and (
-                    vector_index_config["pq"]["enabled"]
+                    vector_index_config.get("pq", {"enabled": False})["enabled"]
                     or vector_index_config.get("sq", {"enabled": False})["enabled"]
                     or vector_index_config.get("rq", {"enabled": False})["enabled"]
                 )
@@ -1153,7 +1176,7 @@ def __check_quantizers(
             or (
                 isinstance(quantizer, _SQConfigUpdate)
                 and (
-                    vector_index_config["pq"]["enabled"]
+                    vector_index_config.get("pq", {"enabled": False})["enabled"]
                     or vector_index_config.get("bq", {"enabled": False})["enabled"]
                     or vector_index_config.get("rq", {"enabled": False})["enabled"]
                 )
@@ -1161,7 +1184,7 @@ def __check_quantizers(
             or (
                 isinstance(quantizer, _RQConfigUpdate)
                 and (
-                    vector_index_config["pq"]["enabled"]
+                    vector_index_config.get("pq", {"enabled": False})["enabled"]
                     or vector_index_config.get("bq", {"enabled": False})["enabled"]
                     or vector_index_config.get("sq", {"enabled": False})["enabled"]
                 )
@@ -1200,7 +1223,7 @@ def merge_with_existing(self, schema: Dict[str, Any]) -> Dict[str, Any]:
                 schema["multiTenancyConfig"]
             )
         if self.vectorIndexConfig is not None:
-            self.__check_quantizers(self.vectorIndexConfig.quantizer, schema["vectorIndexConfig"])
+            self.__check_vectorizer_quantizer(self.vectorIndexConfig, schema["vectorIndexConfig"])
             schema["vectorIndexConfig"] = self.vectorIndexConfig.merge_with_existing(
                 schema["vectorIndexConfig"]
             )
@@ -1228,9 +1251,10 @@ def merge_with_existing(self, schema: Dict[str, Any]) -> Dict[str, Any]:
             )
         if self.vectorizerConfig is not None:
             if isinstance(self.vectorizerConfig, _VectorIndexConfigUpdate):
-                self.__check_quantizers(
-                    self.vectorizerConfig.quantizer, schema["vectorIndexConfig"]
+                self.__check_vectorizer_quantizer(
+                    self.vectorizerConfig, schema["vectorIndexConfig"]
                 )
+
                 schema["vectorIndexConfig"] = self.vectorizerConfig.merge_with_existing(
                     schema["vectorIndexConfig"]
                 )
@@ -1240,10 +1264,10 @@ def merge_with_existing(self, schema: Dict[str, Any]) -> Dict[str, Any]:
                         raise WeaviateInvalidInputError(
                             f"Vector config with name {vc.name} does not exist in the existing vector config"
                         )
-                    self.__check_quantizers(
-                        vc.vectorIndexConfig.quantizer,
-                        schema["vectorConfig"][vc.name]["vectorIndexConfig"],
+                    self.__check_vectorizer_quantizer(
+                        vc.vectorIndexConfig, schema["vectorConfig"][vc.name]["vectorIndexConfig"]
                     )
+
                     schema["vectorConfig"][vc.name]["vectorIndexConfig"] = (
                         vc.vectorIndexConfig.merge_with_existing(
                             schema["vectorConfig"][vc.name]["vectorIndexConfig"]
@@ -1263,10 +1287,10 @@ def merge_with_existing(self, schema: Dict[str, Any]) -> Dict[str, Any]:
                     raise WeaviateInvalidInputError(
                         f"Vector config with name {vc.name} does not exist in the existing vector config"
                     )
-                self.__check_quantizers(
-                    vc.vectorIndexConfig.quantizer,
-                    schema["vectorConfig"][vc.name]["vectorIndexConfig"],
+                self.__check_vectorizer_quantizer(
+                    vc.vectorIndexConfig, schema["vectorConfig"][vc.name]["vectorIndexConfig"]
                 )
+
                 schema["vectorConfig"][vc.name]["vectorIndexConfig"] = (
                     vc.vectorIndexConfig.merge_with_existing(
                         schema["vectorConfig"][vc.name]["vectorIndexConfig"]
@@ -1586,8 +1610,8 @@ def vector_index_type() -> str:
 @dataclass
 class _VectorIndexConfigDynamic(_ConfigBase):
     distance_metric: VectorDistances
-    hnsw: Optional[VectorIndexConfigHNSW]
-    flat: Optional[VectorIndexConfigFlat]
+    hnsw: VectorIndexConfigHNSW
+    flat: VectorIndexConfigFlat
     threshold: Optional[int]
 
     @staticmethod
@@ -2292,7 +2316,6 @@ def dynamic(
         threshold: Optional[int] = None,
         hnsw: Optional[_VectorIndexConfigHNSWUpdate] = None,
         flat: Optional[_VectorIndexConfigFlatUpdate] = None,
-        quantizer: Optional[_BQConfigUpdate] = None,
     ) -> _VectorIndexConfigDynamicUpdate:
         """Create an `_VectorIndexConfigDynamicUpdate` object to update the configuration of the Dynamic vector index.
 
@@ -2305,7 +2328,6 @@ def dynamic(
             threshold=threshold,
             hnsw=hnsw,
             flat=flat,
-            quantizer=quantizer,
         )
 
 
diff --git a/weaviate/collections/classes/config_base.py b/weaviate/collections/classes/config_base.py
index 2ad42bad6..cd0d49594 100644
--- a/weaviate/collections/classes/config_base.py
+++ b/weaviate/collections/classes/config_base.py
@@ -32,7 +32,12 @@ def merge_with_existing(self, schema: Dict[str, Any]) -> Dict[str, Any]:
                 schema[cls_field] = val
             elif isinstance(val, _QuantizerConfigUpdate):
                 quantizers = ["pq", "bq", "sq"]
-                schema[val.quantizer_name()] = val.merge_with_existing(schema[val.quantizer_name()])
+                if val.quantizer_name() in schema:
+                    schema[val.quantizer_name()] = val.merge_with_existing(
+                        schema[val.quantizer_name()]
+                    )
+                else:
+                    schema[val.quantizer_name()] = val.merge_with_existing({})
                 for quantizer in quantizers:
                     if quantizer == val.quantizer_name() or quantizer not in schema:
                         continue
diff --git a/weaviate/collections/classes/config_vector_index.py b/weaviate/collections/classes/config_vector_index.py
index d514bfef7..6c90eded5 100644
--- a/weaviate/collections/classes/config_vector_index.py
+++ b/weaviate/collections/classes/config_vector_index.py
@@ -95,8 +95,6 @@ def _to_dict(self) -> Dict[str, Any]:
 
 
 class _VectorIndexConfigUpdate(_ConfigUpdateModel):
-    quantizer: Optional[_QuantizerConfigUpdate] = Field(exclude=True)
-
     @staticmethod
     @abstractmethod
     def vector_index_type() -> VectorIndexType: ...
@@ -136,13 +134,14 @@ def vector_index_type() -> VectorIndexType:
 
 
 class _VectorIndexConfigHNSWUpdate(_VectorIndexConfigUpdate):
-    dynamicEfMin: Optional[int]
-    dynamicEfMax: Optional[int]
-    dynamicEfFactor: Optional[int]
-    ef: Optional[int]
-    filterStrategy: Optional[VectorFilterStrategy]
-    flatSearchCutoff: Optional[int]
-    vectorCacheMaxObjects: Optional[int]
+    quantizer: Optional[_QuantizerConfigUpdate] = Field(exclude=True)
+    dynamicEfMin: Optional[int] = None
+    dynamicEfMax: Optional[int] = None
+    dynamicEfFactor: Optional[int] = None
+    ef: Optional[int] = None
+    filterStrategy: Optional[VectorFilterStrategy] = None
+    flatSearchCutoff: Optional[int] = None
+    vectorCacheMaxObjects: Optional[int] = None
 
     @staticmethod
     def vector_index_type() -> VectorIndexType:
@@ -150,7 +149,8 @@ def vector_index_type() -> VectorIndexType:
 
 
 class _VectorIndexConfigFlatUpdate(_VectorIndexConfigUpdate):
-    vectorCacheMaxObjects: Optional[int]
+    vectorCacheMaxObjects: Optional[int] = None
+    quantizer: Optional[_QuantizerConfigUpdate] = Field(exclude=True)
 
     @staticmethod
     def vector_index_type() -> VectorIndexType:
@@ -179,9 +179,9 @@ def _to_dict(self) -> dict:
 
 
 class _VectorIndexConfigDynamicUpdate(_VectorIndexConfigUpdate):
-    threshold: Optional[int]
-    hnsw: Optional[_VectorIndexConfigHNSWUpdate]
-    flat: Optional[_VectorIndexConfigFlatUpdate]
+    threshold: Optional[int] = None
+    hnsw: Optional[_VectorIndexConfigHNSWUpdate] = None
+    flat: Optional[_VectorIndexConfigFlatUpdate] = None
 
     @staticmethod
     def vector_index_type() -> VectorIndexType:
diff --git a/weaviate/collections/config/async_.pyi b/weaviate/collections/config/async_.pyi
index 9fcfefdb3..4aff531dc 100644
--- a/weaviate/collections/config/async_.pyi
+++ b/weaviate/collections/config/async_.pyi
@@ -22,6 +22,7 @@ from weaviate.collections.classes.config import (
     _VectorIndexConfigFlatUpdate,
     _VectorIndexConfigHNSWUpdate,
 )
+from weaviate.collections.classes.config_base import _QuantizerConfigUpdate
 from weaviate.collections.classes.config_vector_index import _VectorIndexConfigDynamicUpdate
 from weaviate.connect.v4 import ConnectionAsync
 
@@ -80,3 +81,6 @@ class _ConfigCollectionAsync(_ConfigCollectionExecutor[ConnectionAsync]):
     async def add_vector(
         self, *, vector_config: Union[_VectorConfigCreate, List[_VectorConfigCreate]]
     ) -> None: ...
+    async def update_quantizer(
+        self, *, name: Optional[str] = None, hnsw_quantizer: Optional[_QuantizerConfigUpdate] = None
+    ) -> None: ...
diff --git a/weaviate/collections/config/executor.py b/weaviate/collections/config/executor.py
index e5772b76a..0b5dc4474 100644
--- a/weaviate/collections/config/executor.py
+++ b/weaviate/collections/config/executor.py
@@ -36,9 +36,13 @@
     _ShardStatus,
     _VectorConfigCreate,
     _VectorConfigUpdate,
+    _VectorIndexConfigDynamic,
+    _VectorIndexConfigFlat,
     _VectorIndexConfigFlatUpdate,
+    _VectorIndexConfigHNSW,
     _VectorIndexConfigHNSWUpdate,
 )
+from weaviate.collections.classes.config_base import _QuantizerConfigUpdate
 from weaviate.collections.classes.config_methods import (
     _collection_config_from_json,
     _collection_config_simple_from_json,
@@ -577,3 +581,130 @@ async def _execute() -> None:
             return _execute()
         schema = executor.result(self.__get())
         return executor.result(resp(schema))
+
+    def update_quantizer(
+        self,
+        *,
+        name: Optional[str] = None,
+        hnsw_quantizer: Optional[_QuantizerConfigUpdate] = None,
+        # flat_quantizer: Optional[_QuantizerConfigUpdate] = None,  not yet supported by Weaviate
+    ) -> executor.Result[None]:
+        """Update the quantizer configurations.
+
+        Args:
+            name: Name of the vector to update quantizer settings
+            hnsw_quantizer: The HNSW quantizer configuration to update.
+            flat_quantizer: The flat quantizer configuration to update.
+
+        Raises:
+            weaviate.exceptions.WeaviateConnectionError: If the network connection to Weaviate fails.
+            weaviate.exceptions.UnexpectedStatusCodeError: If Weaviate reports a non-OK status.
+            weaviate.exceptions.WeaviateInvalidInputError: If the vector already exists in the collection.
+        """
+        flat_quantizer = None
+        if hnsw_quantizer is None and flat_quantizer is None:
+            raise WeaviateInvalidInputError("At least one quantizer must be provided.")
+
+        def resp(schema: Dict[str, Any]) -> executor.Result[None]:
+            config = _collection_config_from_json(schema)
+            if config.vector_config is None and config.vector_index_config is None:
+                raise WeaviateInvalidInputError(
+                    "Collection must contain either a vector config or a vector index config."
+                )
+
+            if config.vector_config is None:
+                if isinstance(config.vector_index_config, _VectorIndexConfigHNSW):
+                    if hnsw_quantizer is None:
+                        raise WeaviateInvalidInputError(
+                            "HNSW quantizer must be provided for updating HNSW vector index."
+                        )
+                    vector_index_config = _VectorIndexConfigHNSWUpdate(quantizer=hnsw_quantizer)
+                elif isinstance(config.vector_index_config, _VectorIndexConfigFlat):
+                    if flat_quantizer is None:
+                        raise WeaviateInvalidInputError(
+                            "Flat quantizer must be provided for updating flat vector index."
+                        )
+
+                    vector_index_config = _VectorIndexConfigFlatUpdate(quantizer=flat_quantizer)
+                else:
+                    assert isinstance(config.vector_index_config, _VectorIndexConfigDynamic)
+                    hnsw_update = (
+                        _VectorIndexConfigHNSWUpdate(quantizer=hnsw_quantizer)
+                        if hnsw_quantizer
+                        else None
+                    )
+                    flat_update = (
+                        _VectorIndexConfigFlatUpdate(quantizer=flat_quantizer)
+                        if flat_quantizer
+                        else None
+                    )
+                    vector_index_config = _VectorIndexConfigDynamicUpdate(
+                        hnsw=hnsw_update, flat=flat_update
+                    )
+
+                updated_config = _CollectionConfigUpdate(
+                    vector_index_config=vector_index_config,
+                )
+            else:
+                if name not in config.vector_config:
+                    raise WeaviateInvalidInputError(f"Vector {name} not found in collection.")
+
+                if isinstance(
+                    config.vector_config[name].vector_index_config, _VectorIndexConfigHNSW
+                ):
+                    if hnsw_quantizer is None:
+                        raise WeaviateInvalidInputError(
+                            "HNSW quantizer must be provided for updating HNSW vector index."
+                        )
+                    vector_config = _VectorIndexConfigHNSWUpdate(quantizer=hnsw_quantizer)
+                elif isinstance(
+                    config.vector_config[name].vector_index_config, _VectorIndexConfigFlat
+                ):
+                    if flat_quantizer is None:
+                        raise WeaviateInvalidInputError(
+                            "Flat quantizer must be provided for updating flat vector index."
+                        )
+
+                    vector_config = _VectorIndexConfigFlatUpdate(quantizer=flat_quantizer)
+                else:
+                    assert isinstance(
+                        config.vector_config[name].vector_index_config, _VectorIndexConfigDynamic
+                    )
+                    hnsw_update = (
+                        _VectorIndexConfigHNSWUpdate(quantizer=hnsw_quantizer)
+                        if hnsw_quantizer
+                        else None
+                    )
+                    flat_update = (
+                        _VectorIndexConfigFlatUpdate(quantizer=flat_quantizer)
+                        if flat_quantizer
+                        else None
+                    )
+                    vector_config = _VectorIndexConfigDynamicUpdate(
+                        hnsw=hnsw_update, flat=flat_update
+                    )
+
+                updated_config = _CollectionConfigUpdate(
+                    vector_config=_VectorConfigUpdate(name=name, vector_index_config=vector_config),
+                )
+
+            return executor.execute(
+                response_callback=lambda _: None,
+                method=self._connection.put,
+                path=f"/schema/{self._name}",
+                weaviate_object=updated_config.merge_with_existing(schema),
+                error_msg="Quantizer configuration may not have been updated.",
+                status_codes=_ExpectedStatusCodes(
+                    ok_in=200, error="Update quantizer configuration"
+                ),
+            )
+
+        if isinstance(self._connection, ConnectionAsync):
+
+            async def _execute() -> None:
+                schema = await executor.aresult(self.__get())
+                return await executor.aresult(resp(schema))
+
+            return _execute()
+        schema = executor.result(self.__get())
+        return executor.result(resp(schema))
diff --git a/weaviate/collections/config/sync.pyi b/weaviate/collections/config/sync.pyi
index 89f37615e..f430a3b70 100644
--- a/weaviate/collections/config/sync.pyi
+++ b/weaviate/collections/config/sync.pyi
@@ -22,6 +22,7 @@ from weaviate.collections.classes.config import (
     _VectorIndexConfigFlatUpdate,
     _VectorIndexConfigHNSWUpdate,
 )
+from weaviate.collections.classes.config_base import _QuantizerConfigUpdate
 from weaviate.collections.classes.config_vector_index import _VectorIndexConfigDynamicUpdate
 from weaviate.connect.v4 import ConnectionSync
 
@@ -78,3 +79,6 @@ class _ConfigCollection(_ConfigCollectionExecutor[ConnectionSync]):
     def add_vector(
         self, *, vector_config: Union[_VectorConfigCreate, List[_VectorConfigCreate]]
     ) -> None: ...
+    def update_quantizer(
+        self, *, name: Optional[str] = None, hnsw_quantizer: Optional[_QuantizerConfigUpdate] = None
+    ) -> None: ...