diff --git a/src/mcp/shared/auth.py b/src/mcp/shared/auth.py
index 2debc625e..73a000fc0 100644
--- a/src/mcp/shared/auth.py
+++ b/src/mcp/shared/auth.py
@@ -130,6 +130,7 @@ class OAuthMetadata(BaseModel):
     introspection_endpoint_auth_methods_supported: list[str] | None = None
     introspection_endpoint_auth_signing_alg_values_supported: list[str] | None = None
     code_challenge_methods_supported: list[str] | None = None
+    client_id_metadata_document_supported: bool | None = None
 
 
 class ProtectedResourceMetadata(BaseModel):