# How to fix ImportError: cannot import name 'ModelMetaclass' from 'pydantic.main'

`ModelMetaclass` is not public API in v2. If you just need a model's metaclass, use `type(YourModel)` instead of importing it. If a library does this (motor-odm did), upgrade the library. The class does exist at `pydantic._internal._model_construction`, but that is private and can move between releases.

## The exact error

```text
ImportError: cannot import name 'ModelMetaclass' from 'pydantic.main'
```

## Fix it

1. Replace `from pydantic.main import ModelMetaclass` usage: `type(MyModel)` gives you the metaclass.
   Expected: no import needed

2. If a library does this (motor-odm did), upgrade the library.
   Expected: fixed upstream

3. Last resort: import from `pydantic._internal._model_construction`.
   Expected: works but pinned to internals

## When this applies

v2 code importing ModelMetaclass from pydantic.main

## When this does NOT apply

normal BaseModel subclassing (you never need the metaclass)

## Versions

pydantic v2

## Why it happens

v2 rebuilt the internals; ModelMetaclass left the public namespace.

## Edge cases

Depending on _internal ties you to exact pydantic versions; avoid in libraries.