diff --git a/tests/data/test_defaults.py b/tests/data/test_defaults.py
index 8d14794..1ecbf19 100644
--- a/tests/data/test_defaults.py
+++ b/tests/data/test_defaults.py
@@ -164,6 +164,9 @@ class PaginatedItems(TypedDict):
 
 DEFAULT_COLLABORATOR_RESPONSE_3 = dict(DEFAULT_COLLABORATOR_RESPONSE)
 DEFAULT_COLLABORATOR_RESPONSE_3["id"] = "6X7rjKtP98vG84rK"
+# Forward-compat with Doist/Issues#20418: hidden collaborator emails are
+# currently sent as "hidden@todoist.com", but may become null.
+DEFAULT_COLLABORATOR_RESPONSE_3["email"] = None
 
 DEFAULT_COLLABORATORS_RESPONSE: list[PaginatedResults] = [
     {
diff --git a/todoist_api_python/models.py b/todoist_api_python/models.py
index 5185a3c..55364f7 100644
--- a/todoist_api_python/models.py
+++ b/todoist_api_python/models.py
@@ -142,7 +142,7 @@ class _(JSONPyWizard.Meta):  # noqa:N801
         v1 = True
 
     id: str
-    email: str
+    email: str | None
     name: str