diff --git a/studio/backend/requirements/no-torch-runtime.txt b/studio/backend/requirements/no-torch-runtime.txt
index 3b822ac2a4..f7e761ab42 100644
--- a/studio/backend/requirements/no-torch-runtime.txt
+++ b/studio/backend/requirements/no-torch-runtime.txt
@@ -42,7 +42,9 @@ anyio
 sniffio
 h11
 
-tokenizers
+# Unpinned resolves to 0.23.1+ which breaks `from transformers import
+# AutoConfig`; transformers 4.56..5.3 declares tokenizers<=0.23.0.
+tokenizers<=0.23.0
 transformers>=4.51.3,!=4.52.0,!=4.52.1,!=4.52.2,!=4.52.3,!=4.53.0,!=4.54.0,!=4.55.0,!=4.55.1,!=4.57.0,!=4.57.4,!=4.57.5,!=5.0.0,!=5.1.0,<=5.3.0
 trl>=0.18.2,!=0.19.0,<=0.24.0
 sentence-transformers
diff --git a/tests/python/test_patch_trl_rl_trainers_defensive.py b/tests/python/test_patch_trl_rl_trainers_defensive.py
new file mode 100644
index 0000000000..7c76ac2792
--- /dev/null
+++ b/tests/python/test_patch_trl_rl_trainers_defensive.py
@@ -0,0 +1,69 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved.
+
+"""Regression tests: _patch_trl_rl_trainers must never raise.
+
+The wrapper in unsloth/models/rl.py ring-fences the impl so direct
+callers (CI shims, downstream tools) don't have to. Lock that
+contract here.
+"""
+
+from __future__ import annotations
+
+import pytest
+
+
+pytest.importorskip("trl")
+
+
+def _import_helpers():
+    try:
+        from unsloth.models.rl import (
+            _patch_trl_rl_trainers,
+            _patch_trl_rl_trainers_impl,
+        )
+    except ImportError as e:
+        pytest.skip(f"unsloth.models.rl helpers not importable: {e}")
+    return _patch_trl_rl_trainers, _patch_trl_rl_trainers_impl
+
+
+def test_patch_trl_rl_trainers_swallows_unknown_trainer_name():
+    wrapper, _impl = _import_helpers()
+    assert wrapper("definitely_not_a_real_trainer_xyz") is None
+
+
+def test_patch_trl_rl_trainers_swallows_garbage_input():
+    wrapper, _impl = _import_helpers()
+    for bad in ("", "..", "trainer with space", "sft_trainer; rm -rf /"):
+        assert wrapper(bad) is None, f"raised on input: {bad!r}"
+
+
+def test_impl_is_separately_exposed():
+    # Power users can still call the impl directly for the raising path.
+    _wrapper, impl = _import_helpers()
+    assert callable(impl)
+
+
+def test_wrapper_delegates_to_impl(monkeypatch):
+    from unsloth.models import rl as _rl
+
+    sentinel = object()
+    calls = []
+
+    def _fake_impl(trainer_file):
+        calls.append(trainer_file)
+        return sentinel
+
+    monkeypatch.setattr(_rl, "_patch_trl_rl_trainers_impl", _fake_impl)
+    assert _rl._patch_trl_rl_trainers("sft_trainer") is sentinel
+    assert calls == ["sft_trainer"]
+
+
+def test_wrapper_swallows_impl_exception(monkeypatch):
+    from unsloth.models import rl as _rl
+
+    def _boom(_trainer_file):
+        raise RuntimeError("simulated TRL 1.x rename failure")
+
+    monkeypatch.setattr(_rl, "_patch_trl_rl_trainers_impl", _boom)
+    assert _rl._patch_trl_rl_trainers("sft_trainer") is None
diff --git a/unsloth/models/rl.py b/unsloth/models/rl.py
index ac9b35a822..5200bfefd2 100755
--- a/unsloth/models/rl.py
+++ b/unsloth/models/rl.py
@@ -540,6 +540,20 @@ def _wrap_grpo_generate_and_score(trainer_cls):
 
 
 def _patch_trl_rl_trainers(trainer_file = "grpo_trainer"):
+    # Defensive wrapper: matches patch_trl_rl_trainers()'s try/except so
+    # direct callers don't see exceptions from the impl on TRL versions
+    # that rename or move classes (e.g. TRL 1.x trl.experimental).
+    try:
+        return _patch_trl_rl_trainers_impl(trainer_file)
+    except Exception as e:
+        logger.info(
+            f"Unsloth: Could not patch trl.trainer.{trainer_file}: "
+            f"{type(e).__name__}: {e}"
+        )
+        return
+
+
+def _patch_trl_rl_trainers_impl(trainer_file = "grpo_trainer"):
     # Patch for vLLM and Unsloth PEFT
     import trl
     import trl.trainer