diff --git a/gridfs/asynchronous/grid_file.py b/gridfs/asynchronous/grid_file.py
index 4d6140750..afc1a0f75 100644
--- a/gridfs/asynchronous/grid_file.py
+++ b/gridfs/asynchronous/grid_file.py
@@ -1176,20 +1176,22 @@ class AsyncGridIn:
         raise AttributeError("GridIn object has no attribute '%s'" % name)
 
     def __setattr__(self, name: str, value: Any) -> None:
-        if _IS_SYNC:
-            # For properties of this instance like _buffer, or descriptors set on
-            # the class like filename, use regular __setattr__
-            if name in self.__dict__ or name in self.__class__.__dict__:
-                object.__setattr__(self, name, value)
-            else:
+        # For properties of this instance like _buffer, or descriptors set on
+        # the class like filename, use regular __setattr__
+        if name in self.__dict__ or name in self.__class__.__dict__:
+            object.__setattr__(self, name, value)
+        else:
+            if _IS_SYNC:
                 # All other attributes are part of the document in db.fs.files.
                 # Store them to be sent to server on close() or if closed, send
                 # them now.
                 self._file[name] = value
                 if self._closed:
                     self._coll.files.update_one({"_id": self._file["_id"]}, {"$set": {name: value}})
-        else:
-            object.__setattr__(self, name, value)
+            else:
+                raise AttributeError(
+                    "AsyncGridIn does not support __setattr__. Use AsyncGridIn.set() instead"
+                )
 
     async def set(self, name: str, value: Any) -> None:
         # For properties of this instance like _buffer, or descriptors set on
@@ -1484,6 +1486,17 @@ class AsyncGridOut(io.IOBase):
     _file: Any
     _chunk_iter: Any
 
+    async def __anext__(self) -> bytes:
+        return super().__next__()
+
+    def __next__(self) -> bytes:  # noqa: F811, RUF100
+        if _IS_SYNC:
+            return super().__next__()
+        else:
+            raise TypeError(
+                "AsyncGridOut does not support synchronous iteration. Use `async for` instead"
+            )
+
     async def open(self) -> None:
         if not self._file:
             _disallow_transactions(self._session)
@@ -1511,6 +1524,7 @@ class AsyncGridOut(io.IOBase):
         """Reads a chunk at a time. If the current position is within a
         chunk the remainder of the chunk is returned.
         """
+        await self.open()
         received = len(self._buffer) - self._buffer_pos
         chunk_data = EMPTY
         chunk_size = int(self.chunk_size)
diff --git a/gridfs/synchronous/grid_file.py b/gridfs/synchronous/grid_file.py
index bc2e29a61..80015f96e 100644
--- a/gridfs/synchronous/grid_file.py
+++ b/gridfs/synchronous/grid_file.py
@@ -1166,20 +1166,22 @@ class GridIn:
         raise AttributeError("GridIn object has no attribute '%s'" % name)
 
     def __setattr__(self, name: str, value: Any) -> None:
-        if _IS_SYNC:
-            # For properties of this instance like _buffer, or descriptors set on
-            # the class like filename, use regular __setattr__
-            if name in self.__dict__ or name in self.__class__.__dict__:
-                object.__setattr__(self, name, value)
-            else:
+        # For properties of this instance like _buffer, or descriptors set on
+        # the class like filename, use regular __setattr__
+        if name in self.__dict__ or name in self.__class__.__dict__:
+            object.__setattr__(self, name, value)
+        else:
+            if _IS_SYNC:
                 # All other attributes are part of the document in db.fs.files.
                 # Store them to be sent to server on close() or if closed, send
                 # them now.
                 self._file[name] = value
                 if self._closed:
                     self._coll.files.update_one({"_id": self._file["_id"]}, {"$set": {name: value}})
-        else:
-            object.__setattr__(self, name, value)
+            else:
+                raise AttributeError(
+                    "GridIn does not support __setattr__. Use GridIn.set() instead"
+                )
 
     def set(self, name: str, value: Any) -> None:
         # For properties of this instance like _buffer, or descriptors set on
@@ -1472,6 +1474,15 @@ class GridOut(io.IOBase):
     _file: Any
     _chunk_iter: Any
 
+    def __next__(self) -> bytes:
+        return super().__next__()
+
+    def __next__(self) -> bytes:  # noqa: F811, RUF100
+        if _IS_SYNC:
+            return super().__next__()
+        else:
+            raise TypeError("GridOut does not support synchronous iteration. Use `for` instead")
+
     def open(self) -> None:
         if not self._file:
             _disallow_transactions(self._session)
@@ -1499,6 +1510,7 @@ class GridOut(io.IOBase):
         """Reads a chunk at a time. If the current position is within a
         chunk the remainder of the chunk is returned.
         """
+        self.open()
         received = len(self._buffer) - self._buffer_pos
         chunk_data = EMPTY
         chunk_size = int(self.chunk_size)
diff --git a/pymongo/asynchronous/encryption.py b/pymongo/asynchronous/encryption.py
index 8b63525f2..93484541e 100644
--- a/pymongo/asynchronous/encryption.py
+++ b/pymongo/asynchronous/encryption.py
@@ -304,7 +304,7 @@ class _EncryptionIO(AsyncMongoCryptCallback):  # type: ignore[misc]
 
 
 class RewrapManyDataKeyResult:
-    """Result object returned by a :meth:`~ClientEncryption.rewrap_many_data_key` operation.
+    """Result object returned by a :meth:`~AsyncClientEncryption.rewrap_many_data_key` operation.
 
     .. versionadded:: 4.2
     """
@@ -316,7 +316,7 @@ class RewrapManyDataKeyResult:
     def bulk_write_result(self) -> Optional[BulkWriteResult]:
         """The result of the bulk write operation used to update the key vault
         collection with one or more rewrapped data keys. If
-        :meth:`~ClientEncryption.rewrap_many_data_key` does not find any matching keys to rewrap,
+        :meth:`~AsyncClientEncryption.rewrap_many_data_key` does not find any matching keys to rewrap,
         no bulk write operation will be executed and this field will be
         ``None``.
         """
@@ -506,7 +506,7 @@ def _create_mongocrypt_options(**kwargs: Any) -> MongoCryptOptions:
     return opts
 
 
-class ClientEncryption(Generic[_DocumentType]):
+class AsyncClientEncryption(Generic[_DocumentType]):
     """Explicit client-side field level encryption."""
 
     def __init__(
@@ -519,7 +519,7 @@ class ClientEncryption(Generic[_DocumentType]):
     ) -> None:
         """Explicit client-side field level encryption.
 
-        The ClientEncryption class encapsulates explicit operations on a key
+        The AsyncClientEncryption class encapsulates explicit operations on a key
         vault collection that cannot be done directly on an AsyncMongoClient. Similar
         to configuring auto encryption on an AsyncMongoClient, it is constructed with
         an AsyncMongoClient (to a MongoDB cluster containing the key vault
@@ -1126,7 +1126,7 @@ class ClientEncryption(Generic[_DocumentType]):
         result = await self._key_vault_coll.bulk_write(replacements)
         return RewrapManyDataKeyResult(result)
 
-    async def __aenter__(self) -> ClientEncryption[_DocumentType]:
+    async def __aenter__(self) -> AsyncClientEncryption[_DocumentType]:
         return self
 
     async def __aexit__(self, exc_type: Any, exc_val: Any, exc_tb: Any) -> None:
@@ -1134,7 +1134,7 @@ class ClientEncryption(Generic[_DocumentType]):
 
     def _check_closed(self) -> None:
         if self._encryption is None:
-            raise InvalidOperation("Cannot use closed ClientEncryption")
+            raise InvalidOperation("Cannot use closed AsyncClientEncryption")
 
     async def close(self) -> None:
         """Release resources.
@@ -1142,7 +1142,7 @@ class ClientEncryption(Generic[_DocumentType]):
         Note that using this class in a with-statement will automatically call
         :meth:`close`::
 
-            with ClientEncryption(...) as client_encryption:
+            with AsyncClientEncryption(...) as client_encryption:
                 encrypted = client_encryption.encrypt(value, ...)
                 decrypted = client_encryption.decrypt(encrypted)
 
diff --git a/pymongo/encryption_options.py b/pymongo/encryption_options.py
index 3b0d32a4b..df1302650 100644
--- a/pymongo/encryption_options.py
+++ b/pymongo/encryption_options.py
@@ -70,7 +70,7 @@ class AutoEncryptionOpts:
         users. To configure automatic *decryption* without automatic
         *encryption* set ``bypass_auto_encryption=True``. Explicit
         encryption and explicit decryption is also supported for all users
-        with the :class:`~pymongo.encryption.ClientEncryption` class.
+        with the :class:`~pymongo.asynchronous.encryption.AsyncClientEncryption` and :class:`~pymongo.encryption.ClientEncryption` classes.
 
         See :ref:`automatic-client-side-encryption` for an example.
 
diff --git a/pyproject.toml b/pyproject.toml
index 4380b57e8..8452bfe95 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -126,7 +126,7 @@ module = ["service_identity.*"]
 ignore_missing_imports = true
 
 [[tool.mypy.overrides]]
-module = ["pymongo.synchronous.*", "gridfs.synchronous.*"]
+module = ["pymongo.synchronous.*"]
 warn_unused_ignores = false
 disable_error_code = ["unused-coroutine"]
 
@@ -134,6 +134,10 @@ disable_error_code = ["unused-coroutine"]
 module = ["pymongo.asynchronous.*"]
 warn_unused_ignores = false
 
+[[tool.mypy.overrides]]
+module = ["gridfs.synchronous.*"]
+warn_unused_ignores = false
+disable_error_code = ["unused-coroutine", "no-redef"]
 
 [tool.ruff]
 target-version = "py37"
diff --git a/tools/synchro.py b/tools/synchro.py
index 0c2aff130..65ff3bfe0 100644
--- a/tools/synchro.py
+++ b/tools/synchro.py
@@ -58,6 +58,7 @@ replacements = {
     "_AsyncGridOutChunkIterator": "GridOutChunkIterator",
     "_a_grid_in_property": "_grid_in_property",
     "_a_grid_out_property": "_grid_out_property",
+    "AsyncClientEncryption": "ClientEncryption",
     "AsyncMongoCryptCallback": "MongoCryptCallback",
     "AsyncExplicitEncrypter": "ExplicitEncrypter",
     "AsyncAutoEncrypter": "AutoEncrypter",