diff --git a/src/backend/core/factories.py b/src/backend/core/factories.py
index eeefa8f4b..d918c073f 100644
--- a/src/backend/core/factories.py
+++ b/src/backend/core/factories.py
@@ -2,6 +2,8 @@
 Core application factories
 """
 
+import base64
+
 from django.conf import settings
 from django.contrib.auth.hashers import make_password
 
@@ -28,6 +30,12 @@ YDOC_HELLO_WORLD_BASE64 = (
     "dGV4dENvbG9yAXcHZGVmYXVsdCgA9e7y1Q4eD2JhY2tncm91bmRDb2xvcgF3B2RlZmF1bHQA"
 )
 
+# The same document as the raw Yjs update the collaboration server serves, which
+# is what a test faking `YHubService.get_ydoc` answers with (see the
+# `yhub_content` fixture). The base64 above is the legacy object storage format,
+# only the tests still about that storage have a use for it.
+YDOC_HELLO_WORLD_UPDATE = base64.b64decode(YDOC_HELLO_WORLD_BASE64)
+
 
 class UserFactory(factory.django.DjangoModelFactory):
     """A factory to random users for testing purposes."""
@@ -83,7 +91,10 @@ class DocumentFactory(factory.django.DjangoModelFactory):
 
     title = factory.Sequence(lambda n: f"document{n}")
     excerpt = factory.Sequence(lambda n: f"excerpt{n}")
-    content = YDOC_HELLO_WORLD_BASE64
+    # No content: the collaboration server holds it, and a document built here
+    # is one it knows nothing of. A test needing a document with content fakes
+    # what the collaboration server serves for it (`YHubService.get_ydoc`), and
+    # only the ones about the legacy object storage itself pass `content=`.
     creator = factory.SubFactory(UserFactory)
     deleted_at = None
     link_reach = factory.fuzzy.FuzzyChoice(
diff --git a/src/backend/core/tests/commands/test_index.py b/src/backend/core/tests/commands/test_index.py
index 1b4a42e6c..48be84b4d 100644
--- a/src/backend/core/tests/commands/test_index.py
+++ b/src/backend/core/tests/commands/test_index.py
@@ -11,7 +11,9 @@ from django.db import transaction
 import pytest
 
 from core import factories
+from core.factories import YDOC_HELLO_WORLD_UPDATE
 from core.services.search_indexers import FindDocumentIndexer
+from core.services.yhub_services import YHubService
 from core.utils.yjs import base64_yjs_to_text
 
 # what the fake collaboration server of the indexer_settings fixture serves
@@ -28,7 +30,7 @@ def test_index():
 
     with transaction.atomic():
         doc = factories.DocumentFactory()
-        empty_doc = factories.DocumentFactory(title=None, content="")
+        empty_doc = factories.DocumentFactory(title=None)
         no_title_doc = factories.DocumentFactory(title=None)
 
         factories.UserDocumentAccessFactory(document=doc, user=user)
@@ -41,7 +43,15 @@ def test_index():
         str(no_title_doc.path): {"users": [user.sub]},
     }
 
-    with mock.patch.object(FindDocumentIndexer, "push") as mock_push:
+    # the empty document is the one the collaboration server holds no content
+    # for, and it has no title either: nothing to index
+    def get_ydoc(document):
+        return None if document.pk == empty_doc.pk else YDOC_HELLO_WORLD_UPDATE
+
+    with (
+        mock.patch.object(FindDocumentIndexer, "push") as mock_push,
+        mock.patch.object(YHubService, "get_ydoc", side_effect=get_ydoc),
+    ):
         call_command("index")
 
         push_call_args = [call.args[0] for call in mock_push.call_args_list]
diff --git a/src/backend/core/tests/conftest.py b/src/backend/core/tests/conftest.py
index 9e1ada633..b39af92a7 100644
--- a/src/backend/core/tests/conftest.py
+++ b/src/backend/core/tests/conftest.py
@@ -32,15 +32,32 @@ def mock_user_teams():
         yield mock_teams
 
 
+@pytest.fixture(name="yhub_content")
+def yhub_content_fixture():
+    """
+    Serve the content of every document, as the collaboration server does.
+
+    It owns the content: a document built by the factories has none in the
+    database, and what it holds is whatever this fake answers for it. The mock
+    is yielded, so a test can serve another document (`return_value`), none at
+    all (`return_value = None`) or a different one per document
+    (`side_effect`).
+    """
+    with mock.patch.object(
+        YHubService, "get_ydoc", return_value=factories.YDOC_HELLO_WORLD_UPDATE
+    ) as mock_get_ydoc:
+        yield mock_get_ydoc
+
+
 @pytest.fixture(name="indexer_settings")
 def indexer_settings_fixture(settings):
     """
     Setup valid settings for the document indexer. Clear the indexer cache.
 
     The indexer reads the content of a document from the collaboration server,
-    which is faked here: it serves what the factories wrote in the database, so
-    a document built with `content=""` is one the collaboration server holds no
-    content for.
+    which is faked here: it holds the same content for every document, and a
+    test wanting one without content answers `None` for it (see the
+    `yhub_content` fixture, this is the same fake).
     """
 
     # pylint: disable-next=import-outside-toplevel
@@ -56,12 +73,8 @@ def indexer_settings_fixture(settings):
     settings.SEARCH_URL = "http://localhost:8081/api/v1.0/documents/search/"
     settings.SEARCH_INDEXER_COUNTDOWN = 1
 
-    def get_ydoc(_service, document):
-        """Answer the raw update the collaboration server would serve."""
-        return base64.b64decode(document.content) if document.content else None
-
     with mock.patch.object(
-        YHubService, "get_ydoc", autospec=True, side_effect=get_ydoc
+        YHubService, "get_ydoc", return_value=factories.YDOC_HELLO_WORLD_UPDATE
     ):
         yield settings
 
diff --git a/src/backend/core/tests/documents/test_api_document_versions.py b/src/backend/core/tests/documents/test_api_document_versions.py
index 83b8c7f58..7e5105bb5 100644
--- a/src/backend/core/tests/documents/test_api_document_versions.py
+++ b/src/backend/core/tests/documents/test_api_document_versions.py
@@ -9,11 +9,23 @@ import pytest
 from rest_framework.test import APIClient
 
 from core import factories, models
+from core.factories import YDOC_HELLO_WORLD_BASE64
 from core.tests.conftest import TEAM, USER, VIA
 
 pytestmark = pytest.mark.django_db
 
 
+def create_document(**kwargs):
+    """
+    Create a document holding content in the legacy object storage.
+
+    Versions are the versions of that object, so these tests are the ones still
+    about it: the factories give a document no content anymore, the
+    collaboration server holds it.
+    """
+    return factories.DocumentFactory(content=YDOC_HELLO_WORLD_BASE64, **kwargs)
+
+
 @pytest.mark.parametrize("reach", models.LinkReachChoices.values)
 @pytest.mark.parametrize("role", models.LinkRoleChoices.values)
 def test_api_document_versions_list_anonymous(role, reach):
@@ -21,7 +33,7 @@ def test_api_document_versions_list_anonymous(role, reach):
     Anonymous users should not be allowed to list document versions for a document
     whatever the reach and role.
     """
-    document = factories.DocumentFactory(link_role=role, link_reach=reach)
+    document = create_document(link_role=role, link_reach=reach)
 
     # Accesses and traces for other users should not interfere
     factories.UserDocumentAccessFactory(document=document)
@@ -44,7 +56,7 @@ def test_api_document_versions_list_authenticated_unrelated(reach):
     client = APIClient()
     client.force_login(user)
 
-    document = factories.DocumentFactory(link_reach=reach)
+    document = create_document(link_reach=reach)
     factories.UserDocumentAccessFactory.create_batch(3, document=document)
 
     # The versions of another document to which the user is related should not be listed either
@@ -70,7 +82,7 @@ def test_api_document_versions_list_authenticated_related_success(via, mock_user
     client = APIClient()
     client.force_login(user)
 
-    document = factories.DocumentFactory()
+    document = create_document()
     if via == USER:
         models.DocumentAccess.objects.create(
             document=document,
@@ -125,7 +137,7 @@ def test_api_document_versions_list_authenticated_related_pagination(
     client = APIClient()
     client.force_login(user)
 
-    document = factories.DocumentFactory()
+    document = create_document()
     for i in range(3):
         document.content = f"before {i:d}"
         document.save()
@@ -199,9 +211,9 @@ def test_api_document_versions_list_authenticated_related_pagination_parent(
     client = APIClient()
     client.force_login(user)
 
-    grand_parent = factories.DocumentFactory()
-    parent = factories.DocumentFactory(parent=grand_parent)
-    document = factories.DocumentFactory(parent=parent)
+    grand_parent = create_document()
+    parent = create_document(parent=grand_parent)
+    document = create_document(parent=parent)
     for i in range(3):
         document.content = f"before {i:d}"
         document.save()
@@ -270,7 +282,7 @@ def test_api_document_versions_list_exceeds_max_page_size():
     client = APIClient()
     client.force_login(user)
 
-    document = factories.DocumentFactory(users=[user])
+    document = create_document(users=[user])
     document.content = "version 2"
     document.save()
 
@@ -288,7 +300,7 @@ def test_api_document_versions_retrieve_anonymous(reach):
     Anonymous users should not be allowed to find specific versions for a document with
     restricted or authenticated link reach.
     """
-    document = factories.DocumentFactory(link_reach=reach)
+    document = create_document(link_reach=reach)
     document.content = "new content"
     document.save()
 
@@ -314,7 +326,7 @@ def test_api_document_versions_retrieve_authenticated_unrelated(reach):
     client = APIClient()
     client.force_login(user)
 
-    document = factories.DocumentFactory(link_reach=reach)
+    document = create_document(link_reach=reach)
     document.content = "new content"
     document.save()
 
@@ -340,7 +352,7 @@ def test_api_document_versions_retrieve_authenticated_related(via, mock_user_tea
     client = APIClient()
     client.force_login(user)
 
-    document = factories.DocumentFactory()
+    document = create_document()
     document.content = "new content"
     document.save()
 
@@ -406,9 +418,9 @@ def test_api_document_versions_retrieve_authenticated_related_parent(
     client = APIClient()
     client.force_login(user)
 
-    grand_parent = factories.DocumentFactory()
-    parent = factories.DocumentFactory(parent=grand_parent)
-    document = factories.DocumentFactory(parent=parent)
+    grand_parent = create_document()
+    parent = create_document(parent=grand_parent)
+    document = create_document(parent=parent)
     document.content = "new content"
     document.save()
 
@@ -462,7 +474,7 @@ def test_api_document_versions_retrieve_authenticated_related_parent(
 
 def test_api_document_versions_create_anonymous():
     """Anonymous users should not be allowed to create document versions."""
-    document = factories.DocumentFactory()
+    document = create_document()
 
     response = APIClient().post(
         f"/api/v1.0/documents/{document.id!s}/versions/",
@@ -484,7 +496,7 @@ def test_api_document_versions_create_authenticated_unrelated():
     client = APIClient()
     client.force_login(user)
 
-    document = factories.DocumentFactory()
+    document = create_document()
 
     response = client.post(
         f"/api/v1.0/documents/{document.id!s}/versions/",
@@ -506,7 +518,7 @@ def test_api_document_versions_create_authenticated_related(via, mock_user_teams
     client = APIClient()
     client.force_login(user)
 
-    document = factories.DocumentFactory()
+    document = create_document()
     if via == USER:
         factories.UserDocumentAccessFactory(document=document, user=user)
     elif via == TEAM:
@@ -524,8 +536,10 @@ def test_api_document_versions_create_authenticated_related(via, mock_user_teams
 
 def test_api_document_versions_update_anonymous():
     """Anonymous users should not be allowed to update a document version."""
-    access = factories.UserDocumentAccessFactory()
-    document = access.document
+    document = create_document()
+    factories.UserDocumentAccessFactory(document=document)
+    # a second version of the object: the first one is the latest, which the
+    # listing excludes
     document.content = "new content"
     document.save()
 
@@ -550,8 +564,10 @@ def test_api_document_versions_update_authenticated_unrelated():
     client = APIClient()
     client.force_login(user)
 
-    access = factories.UserDocumentAccessFactory()
-    document = access.document
+    document = create_document()
+    factories.UserDocumentAccessFactory(document=document)
+    # a second version of the object: the first one is the latest, which the
+    # listing excludes
     document.content = "new content"
     document.save()
 
@@ -559,7 +575,7 @@ def test_api_document_versions_update_authenticated_unrelated():
     version_id = document.get_versions_slice()["versions"][0]["version_id"]
 
     response = client.put(
-        f"/api/v1.0/documents/{access.document_id!s}/versions/{version_id:s}/",
+        f"/api/v1.0/documents/{document.id!s}/versions/{version_id:s}/",
         {"foo": "bar"},
         format="json",
     )
@@ -577,7 +593,7 @@ def test_api_document_versions_update_authenticated_related(via, mock_user_teams
     client = APIClient()
     client.force_login(user)
 
-    document = factories.DocumentFactory()
+    document = create_document()
 
     if via == USER:
         factories.UserDocumentAccessFactory(document=document, user=user)
@@ -630,7 +646,7 @@ def test_api_document_versions_delete_authenticated(reach):
     client = APIClient()
     client.force_login(user)
 
-    document = factories.DocumentFactory(link_reach=reach)
+    document = create_document(link_reach=reach)
     document.content = "new content"
     document.save()
 
@@ -655,7 +671,7 @@ def test_api_document_versions_delete_reader_or_editor(via, role, mock_user_team
     client = APIClient()
     client.force_login(user)
 
-    document = factories.DocumentFactory()
+    document = create_document()
     if via == USER:
         factories.UserDocumentAccessFactory(document=document, user=user, role=role)
     elif via == TEAM:
@@ -692,7 +708,7 @@ def test_api_document_versions_delete_administrator_or_owner(via, mock_user_team
     client = APIClient()
     client.force_login(user)
 
-    document = factories.DocumentFactory()
+    document = create_document()
     role = random.choice(["administrator", "owner"])
     if via == USER:
         factories.UserDocumentAccessFactory(document=document, user=user, role=role)
diff --git a/src/backend/core/tests/documents/test_api_documents_duplicate.py b/src/backend/core/tests/documents/test_api_documents_duplicate.py
index 95a982779..7ce23dfda 100644
--- a/src/backend/core/tests/documents/test_api_documents_duplicate.py
+++ b/src/backend/core/tests/documents/test_api_documents_duplicate.py
@@ -2,7 +2,6 @@
 Test file uploads API endpoint for users in impress's core app.
 """
 
-import base64
 import uuid
 from io import BytesIO
 from unittest import mock
@@ -19,6 +18,7 @@ from freezegun import freeze_time
 from rest_framework.test import APIClient
 
 from core import factories, models
+from core.factories import YDOC_HELLO_WORLD_UPDATE
 from core.services.yhub_services import (
     ServiceUnavailableError as YHubServiceUnavailableError,
 )
@@ -31,15 +31,19 @@ def mock_yhub_fixture():
     """
     The content of a document is held by the collaboration server.
 
-    It stands for a server holding the very content the factories gave the
-    documents, which is what an editor connected to it would have saved.
+    It stands for a server holding content for every document, which is what an
+    editor connected to it would have saved; the database holds none of it. A
+    test caring about the content of a given document declares it in
+    `mock_yhub.contents`, keyed by document id.
     """
+    contents = {}
 
     def get_ydoc(document):
-        return base64.b64decode(document.content) if document.content else None
+        return contents.get(document.id, YDOC_HELLO_WORLD_UPDATE)
 
     with mock.patch("core.api.viewsets.YHubService") as mock_service:
         mock_service.return_value.get_ydoc.side_effect = get_ydoc
+        mock_service.contents = contents
         yield mock_service
 
 
@@ -119,17 +123,16 @@ def test_api_documents_duplicate_success(index, mock_yhub):
     )
     ydoc["document-store"] = fragment
     update = ydoc.get_update()
-    base64_content = base64.b64encode(update).decode("utf-8")
 
     # Create documents
     document = factories.DocumentFactory(
         id=document_ids[index],
-        content=base64_content,
         link_reach="restricted",
         users=[user, factories.UserFactory()],
         title="document with an image",
         attachments=[key for key, _ in image_refs],
     )
+    mock_yhub.contents[document.id] = update
     factories.DocumentFactory(id=document_ids[(index + 1) % 3])
     # Don't create document for third ID to check that it doesn't impact access to attachments
 
@@ -144,7 +147,7 @@ def test_api_documents_duplicate_success(index, mock_yhub):
     # the content is copied through the collaboration server
     assert duplicated_document.content is None
     mock_yhub.return_value.create_ydoc.assert_called_once_with(
-        duplicated_document, base64.b64decode(document.content)
+        duplicated_document, update
     )
     assert duplicated_document.creator == user
     assert duplicated_document.link_reach == "restricted"
@@ -247,7 +250,7 @@ def test_api_documents_duplicate_with_accesses_admin(role, mock_yhub):
     # the content is copied through the collaboration server
     assert duplicated_document.content is None
     mock_yhub.return_value.create_ydoc.assert_called_once_with(
-        duplicated_document, base64.b64decode(document.content)
+        duplicated_document, YDOC_HELLO_WORLD_UPDATE
     )
     assert duplicated_document.link_reach == document.link_reach
     assert duplicated_document.link_role == document.link_role
@@ -306,7 +309,7 @@ def test_api_documents_duplicate_with_accesses_non_admin(role, mock_yhub):
     # the content is copied through the collaboration server
     assert duplicated_document.content is None
     mock_yhub.return_value.create_ydoc.assert_called_once_with(
-        duplicated_document, base64.b64decode(document.content)
+        duplicated_document, YDOC_HELLO_WORLD_UPDATE
     )
     assert duplicated_document.link_reach == document.link_reach
     assert duplicated_document.link_role == document.link_role
@@ -358,7 +361,7 @@ def test_api_documents_duplicate_non_root_document(role, mock_yhub):
     # the content is copied through the collaboration server
     assert duplicated_document.content is None
     mock_yhub.return_value.create_ydoc.assert_called_once_with(
-        duplicated_document, base64.b64decode(child.content)
+        duplicated_document, YDOC_HELLO_WORLD_UPDATE
     )
     assert duplicated_document.link_reach == child.link_reach
     assert duplicated_document.link_role == child.link_role
@@ -576,16 +579,15 @@ def test_api_documents_duplicate_with_descendants_and_attachments(mock_yhub):
         ]
     )
     ydoc["document-store"] = fragment
-    update = ydoc.get_update()
-    root_content = base64.b64encode(update).decode("utf-8")
+    root_update = ydoc.get_update()
 
     root = factories.DocumentFactory(
         id=root_id,
         users=[(user, "owner")],
         title="Root with Image",
-        content=root_content,
         attachments=[image_key_root],
     )
+    mock_yhub.contents[root.id] = root_update
 
     # Create child with different attachment
     ydoc_child = pycrdt.Doc()
@@ -595,17 +597,16 @@ def test_api_documents_duplicate_with_descendants_and_attachments(mock_yhub):
         ]
     )
     ydoc_child["document-store"] = fragment_child
-    update_child = ydoc_child.get_update()
-    child_content = base64.b64encode(update_child).decode("utf-8")
+    child_update = ydoc_child.get_update()
 
     # child
-    factories.DocumentFactory(
+    child = factories.DocumentFactory(
         id=child_id,
         parent=root,
         title="Child with Image",
-        content=child_content,
         attachments=[image_key_child],
     )
+    mock_yhub.contents[child.id] = child_update
 
     # Duplicate with descendants
     with mock.patch("core.api.viewsets.posthog_capture") as mock_capture:
@@ -638,8 +639,8 @@ def test_api_documents_duplicate_with_descendants_and_attachments(mock_yhub):
     assert duplicated_root.content is None
     assert dup_child.content is None
     assert mock_yhub.return_value.create_ydoc.call_args_list == [
-        mock.call(duplicated_root, base64.b64decode(root_content)),
-        mock.call(dup_child, base64.b64decode(child_content)),
+        mock.call(duplicated_root, root_update),
+        mock.call(dup_child, child_update),
     ]
 
 
diff --git a/src/backend/core/tests/documents/test_api_documents_formatted_content.py b/src/backend/core/tests/documents/test_api_documents_formatted_content.py
index 7a800a10f..d57074f00 100644
--- a/src/backend/core/tests/documents/test_api_documents_formatted_content.py
+++ b/src/backend/core/tests/documents/test_api_documents_formatted_content.py
@@ -2,7 +2,6 @@
 Tests for Documents API endpoint in impress's core app: convert
 """
 
-import base64
 from unittest.mock import patch
 
 import pytest
@@ -11,6 +10,7 @@ from rest_framework import status
 from rest_framework.test import APIClient
 
 from core import factories
+from core.factories import YDOC_HELLO_WORLD_UPDATE
 from core.services.yhub_services import (
     ServiceUnavailableError as YHubServiceUnavailableError,
 )
@@ -23,15 +23,12 @@ def mock_yhub_fixture():
     """
     The content of a document is held by the collaboration server.
 
-    It stands for a server holding the very content the factories gave the
-    documents, which is what an editor connected to it would have saved.
+    It stands for a server holding content for every document, which is what an
+    editor connected to it would have saved. The documents themselves hold none
+    in the database, nothing writes it there anymore.
     """
-
-    def get_ydoc(document):
-        return base64.b64decode(document.content) if document.content else None
-
     with patch("core.api.viewsets.YHubService") as mock_service:
-        mock_service.return_value.get_ydoc.side_effect = get_ydoc
+        mock_service.return_value.get_ydoc.return_value = YDOC_HELLO_WORLD_UPDATE
         yield mock_service
 
 
@@ -58,7 +55,7 @@ def test_api_documents_formatted_content_public(mock_content, reach, role):
     assert data["title"] == document.title
     assert data["content"] == {"some": "data"}
     mock_content.assert_called_once_with(
-        base64.b64decode(document.content),
+        YDOC_HELLO_WORLD_UPDATE,
         "application/vnd.yjs.doc",
         "application/json",
     )
@@ -117,7 +114,7 @@ def test_api_documents_formatted_content_not_public(
     assert data["title"] == document.title
     assert data["content"] == {"some": "data"}
     mock_content.assert_called_once_with(
-        base64.b64decode(document.content),
+        YDOC_HELLO_WORLD_UPDATE,
         "application/vnd.yjs.doc",
         "application/json",
     )
@@ -147,7 +144,7 @@ def test_api_documents_formatted_content_format(mock_content, content_format, ac
     assert data["title"] == document.title
     assert data["content"] == {"some": "data"}
     mock_content.assert_called_once_with(
-        base64.b64decode(document.content), "application/vnd.yjs.doc", accept
+        YDOC_HELLO_WORLD_UPDATE, "application/vnd.yjs.doc", accept
     )
 
 
@@ -188,9 +185,11 @@ def test_api_documents_formatted_content_nonexistent_document(mock_request):
 
 
 @patch("core.services.converter_services.YdocConverter._request")
-def test_api_documents_formatted_content_empty_document(mock_request):
+def test_api_documents_formatted_content_empty_document(mock_request, mock_yhub):
     """Test that accessing an empty document returns empty content."""
-    document = factories.DocumentFactory(link_reach="public", content="")
+    document = factories.DocumentFactory(link_reach="public")
+    # an empty document is one the collaboration server holds nothing for
+    mock_yhub.return_value.get_ydoc.return_value = None
 
     response = APIClient().get(
         f"/api/v1.0/documents/{document.id!s}/formatted-content/"
@@ -212,7 +211,6 @@ def test_api_documents_formatted_content_from_collaboration_server(
     document = factories.DocumentFactory(link_reach="public")
     mock_content.return_value = {"some": "data"}
     # what the collaboration server holds, edited since Django last saw it
-    mock_yhub.return_value.get_ydoc.side_effect = None
     mock_yhub.return_value.get_ydoc.return_value = b"\x01\x02edited update"
 
     response = APIClient().get(
diff --git a/src/backend/core/tests/test_models_documents.py b/src/backend/core/tests/test_models_documents.py
index 407e239da..570c44084 100644
--- a/src/backend/core/tests/test_models_documents.py
+++ b/src/backend/core/tests/test_models_documents.py
@@ -938,7 +938,7 @@ def test_models_documents_get_versions_slice_pagination(settings):
     settings.DOCUMENT_VERSIONS_PAGE_SIZE = 4
 
     # Create a document with 7 versions
-    document = factories.DocumentFactory()
+    document = factories.DocumentFactory(content=factories.YDOC_HELLO_WORLD_BASE64)
     for i in range(6):
         document.content = f"bar{i:d}"
         document.save()
@@ -997,7 +997,7 @@ def test_models_documents_get_versions_slice_min_datetime():
 
 def test_models_documents_version_duplicate():
     """A new version should be created in object storage only if the content has changed."""
-    document = factories.DocumentFactory()
+    document = factories.DocumentFactory(content=factories.YDOC_HELLO_WORLD_BASE64)
 
     file_key = str(document.pk)
     response = default_storage.connection.meta.client.list_object_versions(
diff --git a/src/backend/core/tests/test_services_search_indexers.py b/src/backend/core/tests/test_services_search_indexers.py
index 2dcc972d1..324b5d374 100644
--- a/src/backend/core/tests/test_services_search_indexers.py
+++ b/src/backend/core/tests/test_services_search_indexers.py
@@ -1,6 +1,5 @@
 """Tests for Documents search indexers"""
 
-from base64 import b64decode
 from functools import partial
 from json import dumps as json_dumps
 from unittest.mock import patch
@@ -231,7 +230,7 @@ def test_services_search_indexers_serialize_document_deleted():
 @pytest.mark.usefixtures("indexer_settings")
 def test_services_search_indexers_serialize_document_empty():
     """Empty documents returns empty content in the serialized json."""
-    document = factories.DocumentFactory(content="", title=None)
+    document = factories.DocumentFactory(title=None)
 
     indexer = FindDocumentIndexer()
     result = indexer.serialize_document(document, "", {})
@@ -366,14 +365,14 @@ def test_services_search_indexers_skip_documents_the_content_of_which_is_unreada
     """
     unreadable, readable = factories.DocumentFactory.create_batch(2)
 
-    def get_ydoc(_service, document):
+    def get_ydoc(document):
         if document.pk == unreadable.pk:
             raise ServiceUnavailableError("yhub is unreachable")
-        return b64decode(document.content)
+        return factories.YDOC_HELLO_WORLD_UPDATE
 
-    # a plain replacement: the indexer_settings fixture already serves the
-    # content of the documents, this test needs one of them to fail
-    with patch.object(YHubService, "get_ydoc", get_ydoc):
+    # the indexer_settings fixture serves content for every document, this
+    # test needs one of them to fail
+    with patch.object(YHubService, "get_ydoc", side_effect=get_ydoc):
         assert FindDocumentIndexer().index() == 1
 
     results = {doc["id"] for doc in mock_push.call_args[0][0]}
@@ -388,11 +387,18 @@ def test_services_search_indexers_ignore_empty_documents(mock_push):
     and only the access data relevant to each batch should be used.
     """
     document = factories.DocumentFactory()
-    factories.DocumentFactory(content="", title="")
+    empty = factories.DocumentFactory(title="")
     empty_title = factories.DocumentFactory(title="")
-    empty_content = factories.DocumentFactory(content="")
+    empty_content = factories.DocumentFactory()
 
-    assert FindDocumentIndexer().index() == 3
+    # a document with no content is one the collaboration server holds none for
+    def get_ydoc(doc):
+        if doc.pk in (empty.pk, empty_content.pk):
+            return None
+        return factories.YDOC_HELLO_WORLD_UPDATE
+
+    with patch.object(YHubService, "get_ydoc", side_effect=get_ydoc):
+        assert FindDocumentIndexer().index() == 3
 
     assert mock_push.call_count == 1
 
@@ -417,10 +423,18 @@ def test_services_search_indexers_skip_empty_batches(mock_push, indexer_settings
 
     document = factories.DocumentFactory()
 
-    # Only empty docs
-    factories.DocumentFactory.create_batch(5, content="", title="")
+    # Only empty docs: no title, and no content in the collaboration server
+    empty = factories.DocumentFactory.create_batch(5, title="")
+    empty_ids = {doc.pk for doc in empty}
 
-    assert FindDocumentIndexer().index() == 1
+    with patch.object(
+        YHubService,
+        "get_ydoc",
+        side_effect=lambda doc: (
+            None if doc.pk in empty_ids else factories.YDOC_HELLO_WORLD_UPDATE
+        ),
+    ):
+        assert FindDocumentIndexer().index() == 1
     assert mock_push.call_count == 1
 
     results = [doc["id"] for doc in mock_push.call_args[0][0]]