●Change8

Migrating to PEFT v0.18.0

Version v0.18.0 introduces 2 breaking changes. This guide details how to update your code.

Released: 11/13/2025

2
Breaking Changes
3
Migration Steps
7
Affected Symbols

⚠️ Check Your Code

If you use any of these symbols, you need to read this guide:

LoraConfigmodel.add_weighted_adapterset_adapterpeft.tuners.tuners_utils.set_adapterpeft.functionalLoraModel.add_weighted_adapterOFT

Breaking Changes

●Issue #1

Python 3.9 is no longer supported. Users must upgrade to Python 3.10 or newer.

●Issue #2

PEFT version < 0.18.0 is incompatible with the imminent Transformers v5 release. Users planning to use Transformers v5 must upgrade PEFT to 0.18.0+.

Migration Steps

  1. 1
    If you are using Python 3.9, upgrade your environment to Python 3.10 or newer.
  2. 2
    If you plan to use Transformers v5, ensure you upgrade PEFT to version 0.18.0 or later.
  3. 3
    If you are using the OFT method, existing checkpoints may yield slightly different results due to numerical stabilization and speed improvements; retraining the adapter is recommended.

Release Summary

This release introduces seven new PEFT methods including RoAd, ALoRA, and DeLoRA, alongside significant enhancements like stable integration interfaces and support for negative weights in weighted LoRA merging. It also drops support for Python 3.9 and requires an upgrade for compatibility with Transformers v5.

Need More Details?

View the full release notes and all changes for PEFT v0.18.0.

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