From 9b22520b33cf08603ffc2b6e0225a4a6db66b4a6 Mon Sep 17 00:00:00 2001
From: oobabooga <112222186+oobabooga@users.noreply.github.com>
Date: Thu, 2 Jul 2026 16:20:25 -0300
Subject: [PATCH] Fix gradient_checkpointing_enable positional arg crash on
 Gemma3N/Gemma4 GRPO

---
 unsloth/models/vision.py | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/unsloth/models/vision.py b/unsloth/models/vision.py
index 5ab55152db..a7a24171c3 100644
--- a/unsloth/models/vision.py
+++ b/unsloth/models/vision.py
@@ -1884,8 +1884,9 @@ def _nonre_checkpoint(function, *args, **kwargs):
         if "gemma3n" in _model_type.lower() or "gemma4" in _model_type.lower():
             _original_gc_enable = model.gradient_checkpointing_enable
 
-            def _gc_enable_reentrant(**kwargs):
-                gc_kwargs = kwargs.get("gradient_checkpointing_kwargs", {}) or {}
+            def _gc_enable_reentrant(gradient_checkpointing_kwargs = None, **kwargs):
+                # TRL's disable_gradient_checkpointing re-enables this positionally; HF/PEFT/notebooks by keyword.
+                gc_kwargs = dict(gradient_checkpointing_kwargs or {})
                 gc_kwargs["use_reentrant"] = True
                 kwargs["gradient_checkpointing_kwargs"] = gc_kwargs
                 return _original_gc_enable(**kwargs)