"Invalid JSON payload" error when using Pydantic schema with Gemini

I am using the following code:

from typing import List

import llm
from pydantic import BaseModel


PROMPT = """
Extract financial data and current liabilities from the balance sheet
provided in TJX's 10-K filing. Provide values for 2023 and 2024.
"""

class CapitalEmployed(BaseModel):
    year: int
    total_assets: str
    cash: str
    accounts_payable: str
    merchandise_credits: str
    dividends_payable: str
    sales_taxes: str
    other_liabilities: str
    goodwill: str


class Schema(BaseModel):
    items: List[CapitalEmployed]


model = llm.get_model("gemini-2.0-pro-exp-02-05")

response = model.prompt(
    PROMPT,
    attachments=[llm.Attachment(url="https://investor.tjx.com/static-files/051d2f5a-1839-4131-bda4-a485eb755d83")],
    schema=Schema,
)

print(response.text())

I expect this code to return a list of items but I get the following error:

Traceback (most recent call last):
  File "/home/jonathans/llm-scraping/test.py", line 36, in <module>
    print(response.text())
  File "/home/jonathans/llm-scraping/.venv/lib/python3.9/site-packages/llm/models.py", line 424, in text
    self._force()
  File "/home/jonathans/llm-scraping/.venv/lib/python3.9/site-packages/llm/models.py", line 421, in _force
    list(self)
  File "/home/jonathans/llm-scraping/.venv/lib/python3.9/site-packages/llm/models.py", line 467, in __iter__
    for chunk in self.model.execute(
  File "/home/jonathans/llm-scraping/.venv/lib/python3.9/site-packages/llm_gemini.py", line 344, in execute
    raise llm.ModelError(event["error"]["message"])
llm.errors.ModelError: Invalid JSON payload received. Unknown name "$defs" at 'generation_config.response_schema': Cannot find field.
Invalid JSON payload received. Unknown name "$ref" at 'generation_config.response_schema.properties[0].value.items': Cannot find field.

Start at llm_gemini.py around execute() line 344 and trace how the Pydantic Schema becomes generation_config.response_schema. Reproduce the supplied example and inspect the resulting $defs and $ref fields; done means the request no longer raises the reported Invalid JSON payload errors.