diff --git a/.github/workflows/security-audit.yml b/.github/workflows/security-audit.yml
index 27eafbedea..008a972a88 100644
--- a/.github/workflows/security-audit.yml
+++ b/.github/workflows/security-audit.yml
@@ -228,7 +228,15 @@ jobs:
           with open("pyproject.toml", "rb") as f:
               d = tomllib.load(f)
           core = d["project"]["dependencies"]
-          extras = d["project"]["optional-dependencies"]["huggingfacenotorch"]
+          try:
+              extras = d["project"]["optional-dependencies"]["huggingfacenotorch"]
+          except KeyError:
+              # A bare KeyError here reads as a generic crash, which is how this
+              # went unnoticed on the pip branch for three weeks.
+              raise SystemExit(
+                  "pyproject.toml has no [huggingfacenotorch] extra, so the hf-stack "
+                  "scan set cannot be built. Add the extra, or update this workflow."
+              )
           print("# Auto-generated from pyproject.toml by security-audit.yml.")
           print("# core deps + huggingfacenotorch extras.")
           for spec in core + extras:
@@ -821,7 +829,15 @@ jobs:
           with open("pyproject.toml", "rb") as f:
               d = tomllib.load(f)
           core = d["project"]["dependencies"]
-          extras = d["project"]["optional-dependencies"]["huggingfacenotorch"]
+          try:
+              extras = d["project"]["optional-dependencies"]["huggingfacenotorch"]
+          except KeyError:
+              # A bare KeyError here reads as a generic crash, which is how this
+              # went unnoticed on the pip branch for three weeks.
+              raise SystemExit(
+                  "pyproject.toml has no [huggingfacenotorch] extra, so the hf-stack "
+                  "scan set cannot be built. Add the extra, or update this workflow."
+              )
           print("# Auto-generated from pyproject.toml by security-audit.yml.")
           print("# core deps + huggingfacenotorch extras.")
           for spec in core + extras:
diff --git a/pyproject.toml b/pyproject.toml
index 0f57ecf4df..f88faee35d 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1224,8 +1224,11 @@ intel = [
 ]
 amd = [
     "unsloth[huggingfacenotorch]",
-    "bitsandbytes>=0.49.1 ; ('linux' in sys_platform) and (platform_machine == 'AMD64' or platform_machine == 'x86_64' or platform_machine == 'aarch64')",
-    "bitsandbytes>=0.49.1 ; (sys_platform == 'win32') and (platform_machine == 'AMD64' or platform_machine == 'x86_64')",
+    # 4-bit decode is unreliable on ROCm before 0.50.0, the first PyPI release
+    # carrying the full path: blocksize/warp decoupling (bnb #1887), fused SIMT
+    # GEMM on RDNA (#1979), RDNA3/4 workgroup fix (#2012).
+    "bitsandbytes>=0.50.0 ; ('linux' in sys_platform) and (platform_machine == 'AMD64' or platform_machine == 'x86_64' or platform_machine == 'aarch64')",
+    "bitsandbytes>=0.50.0 ; (sys_platform == 'win32') and (platform_machine == 'AMD64' or platform_machine == 'x86_64')",
 ]
 rocm702-torch280 = [
     "unsloth[amd]",
diff --git a/tests/python/test_amd_extras_contract.py b/tests/python/test_amd_extras_contract.py
new file mode 100644
index 0000000000..ce6d1e0b33
--- /dev/null
+++ b/tests/python/test_amd_extras_contract.py
@@ -0,0 +1,102 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved.
+
+"""Contract tests for the amd / huggingfacenotorch extras.
+
+security-audit.yml builds its hf-stack scan set by indexing
+[huggingfacenotorch] straight out of pyproject.toml. When the pip release
+branch shipped without that extra, four security jobs died on a bare
+KeyError for three weeks and nobody noticed, because the failure looked
+like a generic Python crash rather than a missing extra.
+"""
+
+from __future__ import annotations
+
+import re
+import sys
+from pathlib import Path
+
+import pytest
+from packaging.specifiers import SpecifierSet
+from packaging.version import Version
+
+REPO_ROOT = Path(__file__).resolve().parents[2]
+PYPROJECT = REPO_ROOT / "pyproject.toml"
+SECURITY_AUDIT = REPO_ROOT / ".github" / "workflows" / "security-audit.yml"
+
+# 4-bit decode is unreliable on ROCm before 0.50.0, the first PyPI release
+# carrying the full path (bnb #1887, #1979, #2012).
+BNB_MIN = Version("0.50.0")
+
+
+def _extras() -> dict[str, list[str]]:
+    if sys.version_info >= (3, 11):
+        import tomllib
+    else:
+        tomllib = pytest.importorskip("tomli")
+    data = tomllib.loads(PYPROJECT.read_text(encoding = "utf-8"))
+    return data["project"]["optional-dependencies"]
+
+
+def _project_name(spec: str) -> str:
+    """Leading distribution name of a PEP 508 requirement, lowercased."""
+    return re.split(r"[<>=!~;\[\s@]", spec.strip(), maxsplit = 1)[0].strip().lower()
+
+
+class TestExtrasExist:
+    """Both extras must be present, on every branch."""
+
+    @pytest.mark.parametrize("name", ["huggingfacenotorch", "amd"])
+    def test_extra_present(self, name: str):
+        assert name in _extras(), f"pyproject.toml is missing the [{name}] extra"
+
+    def test_amd_pulls_the_no_torch_stack(self):
+        assert any(
+            s.replace(" ", "") == "unsloth[huggingfacenotorch]" for s in _extras()["amd"]
+        ), "the amd extra must pull unsloth[huggingfacenotorch]"
+
+
+class TestHuggingfaceNoTorchIsTorchFree:
+    """The whole point of the extra is that it names no torch distribution."""
+
+    @pytest.mark.parametrize("banned", ["torch", "torchvision"])
+    def test_no_torch_distribution(self, banned: str):
+        named = [s for s in _extras()["huggingfacenotorch"] if _project_name(s) == banned]
+        assert not named, f"[huggingfacenotorch] must not name {banned}: {named}"
+
+
+class TestAmdBitsandbytesFloor:
+    """Keeps the pre-0.50.0 ROCm range out of the AMD install path."""
+
+    def test_every_marker_line_excludes_the_broken_range(self):
+        specs = [s for s in _extras()["amd"] if _project_name(s) == "bitsandbytes"]
+        assert specs, "the amd extra must pin bitsandbytes"
+        for spec in specs:
+            requirement = spec.split(";", 1)[0].strip()
+            allowed = SpecifierSet(requirement[len("bitsandbytes") :].strip())
+            assert not allowed.contains(
+                Version("0.49.2")
+            ), f"{requirement} still admits bnb 0.49.2, which predates the ROCm 4-bit fixes"
+            assert allowed.contains(BNB_MIN), f"{requirement} excludes the fixed release {BNB_MIN}"
+
+
+class TestSecurityAuditWorkflowStaysInSync:
+    """Every extra the audit workflow indexes has to actually exist.
+
+    This is the generic form of the failure: the workflow reaches into
+    pyproject.toml by name, so any rename or omission takes out the scan
+    jobs rather than the branch that caused it.
+    """
+
+    def test_indexed_extras_exist(self):
+        referenced = set(
+            re.findall(
+                r'optional-dependencies"\]\["([^"]+)"\]',
+                SECURITY_AUDIT.read_text(encoding = "utf-8"),
+            )
+        )
+        assert referenced, "expected security-audit.yml to index at least one extra"
+        missing = sorted(referenced - set(_extras()))
+        assert (
+            not missing
+        ), f"security-audit.yml indexes extras that pyproject.toml lacks: {missing}"