diff --git a/src/mcp/server/auth/handlers/register.py b/src/mcp/server/auth/handlers/register.py
index b34f893f3..120b1cf09 100644
--- a/src/mcp/server/auth/handlers/register.py
+++ b/src/mcp/server/auth/handlers/register.py
@@ -69,20 +69,20 @@ async def handle(self, request: Request) -> Response:
                     status_code=400,
                 )
         grant_types_set: set[str] = set(client_metadata.grant_types)
-        valid_sets = [
+        required_sets = [
             {"authorization_code", "refresh_token"},
             {"client_credentials"},
             {"token_exchange"},
             {"client_credentials", "token_exchange"},
         ]
 
-        if grant_types_set not in valid_sets:
+        if not any(required_set.issubset(grant_types_set) for required_set in required_sets):
             return PydanticJSONResponse(
                 content=RegistrationErrorResponse(
                     error="invalid_client_metadata",
                     error_description=(
-                        "grant_types must be authorization_code and refresh_token "
-                        "or client_credentials or token exchange or client_credentials and token_exchange"
+                        "grant_types must include authorization_code and refresh_token, "
+                        "client_credentials, token_exchange, or client_credentials and token_exchange"
                     ),
                 ),
                 status_code=400,
diff --git a/src/mcp/shared/auth.py b/src/mcp/shared/auth.py
index bf37a7b57..c7b273d29 100644
--- a/src/mcp/shared/auth.py
+++ b/src/mcp/shared/auth.py
@@ -47,13 +47,15 @@ class OAuthClientMetadata(BaseModel):
     # client_secret_post;
     # ie: we do not support client_secret_basic
     token_endpoint_auth_method: Literal["none", "client_secret_post"] = "client_secret_post"
-    # grant_types: this implementation supports authorization_code, refresh_token, client_credentials, & token_exchange
+    # grant_types: this implementation supports authorization_code, refresh_token, client_credentials, token_exchange,
+    # and allows additional grant types provided by the client (e.g. device code)
     grant_types: list[
         Literal[
             "authorization_code",
             "refresh_token",
             "client_credentials",
             "token_exchange",
+            "urn:ietf:params:oauth:grant-type:device_code",
         ]
     ] = [
         "authorization_code",