diff --git a/docs/vertexai/services.rst b/docs/vertexai/services.rst
index 7af0aed8b3..72ab574d86 100644
--- a/docs/vertexai/services.rst
+++ b/docs/vertexai/services.rst
@@ -11,6 +11,10 @@ Vertex AI SDK
     :show-inheritance:
     :inherited-members:
 
+.. automodule:: vertexai.language_models._language_models
+    :no-members:
+    :private-members: _TunableModelMixin
+
 .. automodule:: vertexai.preview
     :members:
     :show-inheritance: