diff --git a/google/cloud/firestore_v1/async_collection.py b/google/cloud/firestore_v1/async_collection.py
index aa09e3d9a..70676360e 100644
--- a/google/cloud/firestore_v1/async_collection.py
+++ b/google/cloud/firestore_v1/async_collection.py
@@ -110,7 +110,7 @@ async def list_documents(self, page_size=None):
         """
         parent, _ = self._parent_info()
 
-        iterator = self._client._firestore_api.list_documents(
+        iterator = await self._client._firestore_api.list_documents(
             request={
                 "parent": parent,
                 "collection_id": self.id,
diff --git a/tests/unit/v1/test_async_collection.py b/tests/unit/v1/test_async_collection.py
index 2352e5739..d205cfbd2 100644
--- a/tests/unit/v1/test_async_collection.py
+++ b/tests/unit/v1/test_async_collection.py
@@ -17,6 +17,7 @@
 import aiounittest
 
 import mock
+from tests.unit.v1.test__helpers import AsyncMock
 
 
 class MockAsyncIter:
@@ -196,7 +197,6 @@ async def _list_documents_helper(self, page_size=None):
         from google.api_core.page_iterator import Iterator
         from google.api_core.page_iterator import Page
         from google.cloud.firestore_v1.async_document import AsyncDocumentReference
-        from google.cloud.firestore_v1.services.firestore.client import FirestoreClient
         from google.cloud.firestore_v1.types.document import Document
 
         class _Iterator(Iterator):
@@ -216,9 +216,10 @@ def _next_page(self):
             Document(name=template.format(document_id)) for document_id in document_ids
         ]
         iterator = _Iterator(pages=[documents])
-        api_client = mock.create_autospec(FirestoreClient)
-        api_client.list_documents.return_value = iterator
-        client._firestore_api_internal = api_client
+        firestore_api = AsyncMock()
+        firestore_api.mock_add_spec(spec=["list_documents"])
+        firestore_api.list_documents.return_value = iterator
+        client._firestore_api_internal = firestore_api
         collection = self._make_one("collection", client=client)
 
         if page_size is not None:
@@ -234,7 +235,7 @@ def _next_page(self):
             self.assertEqual(document.id, document_id)
 
         parent, _ = collection._parent_info()
-        api_client.list_documents.assert_called_once_with(
+        firestore_api.list_documents.assert_called_once_with(
             request={
                 "parent": parent,
                 "collection_id": collection.id,