diff --git a/.github/actions/install_unix_deps/action.yml b/.github/actions/install_unix_deps/action.yml
index b0a1831abf2..bd44fe9f52b 100644
--- a/.github/actions/install_unix_deps/action.yml
+++ b/.github/actions/install_unix_deps/action.yml
@@ -1,4 +1,4 @@
-# SPDX-FileCopyrightText: Copyright (c) 2024-2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+# SPDX-FileCopyrightText: Copyright (c) 2024-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
 #
 # SPDX-License-Identifier: Apache-2.0
 
diff --git a/.github/copy-pr-bot.yaml b/.github/copy-pr-bot.yaml
index e2fc4a5f4a2..1c328793a11 100644
--- a/.github/copy-pr-bot.yaml
+++ b/.github/copy-pr-bot.yaml
@@ -1,4 +1,4 @@
-# SPDX-FileCopyrightText: Copyright (c) 2024-2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+# SPDX-FileCopyrightText: Copyright (c) 2024-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
 # SPDX-License-Identifier: Apache-2.0
 
 # Configuration file for `copy-pr-bot` GitHub App
diff --git a/.github/workflows/ci-nightly.yml b/.github/workflows/ci-nightly.yml
index 0abfdd626cb..75425ef0627 100644
--- a/.github/workflows/ci-nightly.yml
+++ b/.github/workflows/ci-nightly.yml
@@ -65,7 +65,7 @@ jobs:
 
       - name: Run CI tools unit tests
         run: |
-          python -m pip install pytest pyyaml==6.0.3
+          python -m pip install pytest pyyaml==6.0.3 pathspec==0.12.1
           # Standalone CI tool tests; skip repo-root conftest.py (imports cuda.pathfinder).
           python -m pytest -v --noconftest ci/tools/tests
 
diff --git a/.github/workflows/pre-commit.yml b/.github/workflows/pre-commit.yml
index 40c4636eb2a..b8efab0f610 100644
--- a/.github/workflows/pre-commit.yml
+++ b/.github/workflows/pre-commit.yml
@@ -58,10 +58,17 @@ jobs:
 
       # PR workflows run from the merge revision; check out that same revision
       # so their helper scripts and configuration stay in sync.
+      # check_spdx.py runs `git log -1 -- <file>` to find the year each file last
+      # changed (copyright-year enforcement), so it needs the full commit history.
+      # In a shallow clone every file looks like it was introduced by the tip
+      # commit, so each would be judged against the tip commit's year.
+      # blob:none keeps all commits and trees but skips historical file contents,
+      # which a path-limited `git log` does not read.
       - name: Checkout repository
         uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1  # v7.0.1
         with:
-          fetch-depth: 1
+          fetch-depth: 0
+          filter: blob:none
           persist-credentials: false
 
       - name: Set up Python
diff --git a/ci/tools/guess_latest.sh b/ci/tools/guess_latest.sh
index 8a0a13034ca..f9d383f2094 100644
--- a/ci/tools/guess_latest.sh
+++ b/ci/tools/guess_latest.sh
@@ -1,5 +1,5 @@
 #!/bin/bash
-# SPDX-FileCopyrightText: Copyright (c) 2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+# SPDX-FileCopyrightText: Copyright (c) 2025-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
 #
 # SPDX-License-Identifier: Apache-2.0
 
diff --git a/ci/tools/tests/test_check_spdx.py b/ci/tools/tests/test_check_spdx.py
new file mode 100644
index 00000000000..b5e7afd6fa8
--- /dev/null
+++ b/ci/tools/tests/test_check_spdx.py
@@ -0,0 +1,195 @@
+# SPDX-FileCopyrightText: Copyright (c) 2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+# SPDX-License-Identifier: Apache-2.0
+
+"""Tests for the copyright-year rule in toolshed/check_spdx.py.
+
+The rule must give the same answer however the hook is invoked (``git commit``,
+``pre-commit run --all-files``, CI), so each test builds a throwaway git repository
+with controlled commit dates and runs the script against it. Years are derived from
+the current year so the tests do not expire.
+
+    python -m pytest ci/tools/tests/test_check_spdx.py -v --noconftest
+"""
+
+from __future__ import annotations
+
+import datetime
+import os
+import shutil
+import subprocess
+import sys
+from pathlib import Path
+
+import pytest
+
+pytest.importorskip("pathspec", reason="check_spdx.py requires pathspec")
+
+REPO = Path(__file__).resolve().parents[3]
+CHECKER = REPO / "toolshed" / "check_spdx.py"
+LICENSE = REPO / "LICENSE"
+
+CURRENT_YEAR = datetime.datetime.now(tz=datetime.UTC).year
+SAMPLE = "toolshed/sample.py"
+
+CONTENT = (
+    "# SPDX-FileCopyrightText: Copyright (c) {years} NVIDIA CORPORATION & AFFILIATES. All rights reserved.\n"
+    "# SPDX-License-Identifier: Apache-2.0\n"
+    "\n"
+    "pass\n"
+)
+
+
+def git(repo, *args, year=None):
+    env = dict(os.environ)
+    env.update(
+        GIT_AUTHOR_NAME="Test",
+        GIT_AUTHOR_EMAIL="test@example.com",
+        GIT_COMMITTER_NAME="Test",
+        GIT_COMMITTER_EMAIL="test@example.com",
+    )
+    if year is not None:
+        date = f"{year}-06-15T12:00:00+0000"
+        env.update(GIT_AUTHOR_DATE=date, GIT_COMMITTER_DATE=date)
+    subprocess.run(  # noqa: S603
+        ["git", "-c", "commit.gpgsign=false", *args],  # noqa: S607
+        cwd=repo,
+        env=env,
+        check=True,
+        capture_output=True,
+    )
+
+
+def commit(repo, relpath, years, *, year):
+    path = repo / relpath
+    path.parent.mkdir(parents=True, exist_ok=True)
+    path.write_text(CONTENT.format(years=years), encoding="utf-8")
+    git(repo, "add", relpath)
+    git(repo, "commit", "-m", f"add {relpath}", year=year)
+    return path
+
+
+def run_checker(repo, *args):
+    # The script reads LICENSE and runs git relative to the working directory,
+    # as pre-commit does from the repository root.
+    return subprocess.run(  # noqa: S603
+        [sys.executable, str(CHECKER), *args, SAMPLE],
+        cwd=repo,
+        capture_output=True,
+        text=True,
+        check=False,
+    )
+
+
+@pytest.fixture
+def repo(tmp_path):
+    git(tmp_path, "init")
+    shutil.copy(LICENSE, tmp_path / "LICENSE")
+    git(tmp_path, "add", "LICENSE")
+    git(tmp_path, "commit", "-m", "init", year=CURRENT_YEAR - 5)
+    return tmp_path
+
+
+@pytest.mark.agent_authored(model="claude-sonnet-5.5")
+@pytest.mark.parametrize(
+    ("commit_age", "copyright_age", "passes"),
+    [
+        # Not modified this year, so last year's copyright is still correct.
+        pytest.param(1, 1, True, id="untouched-since-last-year"),
+        # The bug in #2273: committed this year, nothing staged, stale copyright.
+        pytest.param(0, 1, False, id="committed-this-year-stale-copyright"),
+    ],
+)
+def test_committed_file_is_checked_against_its_last_commit_year(repo, commit_age, copyright_age, passes):
+    commit(repo, SAMPLE, str(CURRENT_YEAR - copyright_age), year=CURRENT_YEAR - commit_age)
+
+    result = run_checker(repo)
+
+    assert (result.returncode == 0) is passes, result.stdout + result.stderr
+    assert ("OUTDATED" in result.stdout) is (not passes)
+
+
+@pytest.mark.agent_authored(model="claude-sonnet-5.5")
+def test_staged_edit_requires_current_year_and_fix_writes_it(repo):
+    # The `git commit` path: the edited file is staged when the hook runs.
+    path = commit(repo, SAMPLE, str(CURRENT_YEAR - 3), year=CURRENT_YEAR - 2)
+    path.write_text(path.read_text(encoding="utf-8") + "# edited\n", encoding="utf-8")
+    git(repo, "add", SAMPLE)
+
+    check = run_checker(repo)
+    assert check.returncode == 1, check.stdout + check.stderr
+    assert f"(expected '{CURRENT_YEAR}')" in check.stdout
+
+    # --fix reports that it changed something, as the hook always has.
+    fix = run_checker(repo, "--fix")
+    assert fix.returncode == 1, fix.stdout + fix.stderr
+    assert f"Copyright (c) {CURRENT_YEAR - 3}-{CURRENT_YEAR} " in path.read_text(encoding="utf-8")
+
+    # The rewrite is stable: a second run accepts the file.
+    assert run_checker(repo).returncode == 0
+
+
+@pytest.mark.agent_authored(model="claude-sonnet-5.5")
+def test_fix_of_clean_stale_file_survives_being_committed(repo):
+    # Stale relative to an old commit, with nothing staged (for example a manual
+    # `pre-commit run --all-files`).
+    path = commit(repo, SAMPLE, str(CURRENT_YEAR - 3), year=CURRENT_YEAR - 2)
+
+    fix = run_checker(repo, "--fix")
+    assert fix.returncode == 1, fix.stdout + fix.stderr
+    # Not the older last-commit year: committing the fix is a change made this year.
+    assert f"Copyright (c) {CURRENT_YEAR - 3}-{CURRENT_YEAR} " in path.read_text(encoding="utf-8")
+
+    git(repo, "add", SAMPLE)
+    git(repo, "commit", "-m", "fix copyright", year=CURRENT_YEAR)
+
+    # The fix must not demand another fix once it is part of this year's history.
+    assert run_checker(repo).returncode == 0
+
+
+@pytest.mark.parametrize(
+    ("date", "passes"),
+    [
+        pytest.param(f"{CURRENT_YEAR - 1}-12-31T23:30:00-0800", False, id="utc-year-after-recorded-year"),
+        pytest.param(f"{CURRENT_YEAR}-01-01T00:30:00+1400", True, id="utc-year-before-recorded-year"),
+    ],
+)
+@pytest.mark.agent_authored(model="gpt-6")
+def test_committed_file_uses_utc_year_across_new_year(repo, monkeypatch, date, passes):
+    monkeypatch.setenv("GIT_AUTHOR_DATE", date)
+    monkeypatch.setenv("GIT_COMMITTER_DATE", date)
+    commit(repo, SAMPLE, str(CURRENT_YEAR - 1), year=None)
+
+    result = run_checker(repo)
+
+    assert (result.returncode == 0) is passes, result.stdout + result.stderr
+    assert ("OUTDATED" in result.stdout) is (not passes)
+
+
+@pytest.mark.agent_authored(model="gpt-6")
+def test_signed_last_commit_with_show_signature_enabled(repo):
+    ssh_keygen = shutil.which("ssh-keygen")
+    if ssh_keygen is None:
+        pytest.skip("ssh-keygen is required to create a signed commit")
+
+    signing_key = repo / "signing_key"
+    subprocess.run(  # noqa: S603
+        [ssh_keygen, "-q", "-t", "ed25519", "-N", "", "-f", str(signing_key)],
+        check=True,
+        capture_output=True,
+    )
+    allowed_signers = repo / "allowed_signers"
+    allowed_signers.write_text(
+        "test@example.com " + signing_key.with_suffix(".pub").read_text(encoding="utf-8"), encoding="utf-8"
+    )
+    git(repo, "config", "gpg.format", "ssh")
+    git(repo, "config", "user.signingkey", str(signing_key))
+    git(repo, "config", "gpg.ssh.allowedSignersFile", str(allowed_signers))
+    git(repo, "config", "log.showSignature", "true")
+    path = commit(repo, SAMPLE, str(CURRENT_YEAR), year=CURRENT_YEAR)
+    path.write_text(path.read_text(encoding="utf-8") + "# signed edit\n", encoding="utf-8")
+    git(repo, "add", SAMPLE)
+    git(repo, "-c", "commit.gpgsign=true", "commit", "-m", "signed edit", year=CURRENT_YEAR)
+
+    result = run_checker(repo)
+
+    assert result.returncode == 0, result.stdout + result.stderr
diff --git a/cuda_core/DESCRIPTION.rst b/cuda_core/DESCRIPTION.rst
index 0d725a2520a..9759aed8731 100644
--- a/cuda_core/DESCRIPTION.rst
+++ b/cuda_core/DESCRIPTION.rst
@@ -1,4 +1,4 @@
-.. SPDX-FileCopyrightText: Copyright (c) 2024-2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+.. SPDX-FileCopyrightText: Copyright (c) 2024-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
 .. SPDX-License-Identifier: Apache-2.0
 
 *******************************************************
diff --git a/cuda_core/cuda/core/_memory/_graph_memory_resource.pxd b/cuda_core/cuda/core/_memory/_graph_memory_resource.pxd
index 492aa23cd3d..d28c638c04f 100644
--- a/cuda_core/cuda/core/_memory/_graph_memory_resource.pxd
+++ b/cuda_core/cuda/core/_memory/_graph_memory_resource.pxd
@@ -1,4 +1,4 @@
-# SPDX-FileCopyrightText: Copyright (c) 2024-2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+# SPDX-FileCopyrightText: Copyright (c) 2024-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
 #
 # SPDX-License-Identifier: Apache-2.0
 
diff --git a/cuda_core/cuda/core/_utils/__init__.py b/cuda_core/cuda/core/_utils/__init__.py
index 79599c77db0..644dbb92e75 100644
--- a/cuda_core/cuda/core/_utils/__init__.py
+++ b/cuda_core/cuda/core/_utils/__init__.py
@@ -1,3 +1,3 @@
-# SPDX-FileCopyrightText: Copyright (c) 2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+# SPDX-FileCopyrightText: Copyright (c) 2025-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
 #
 # SPDX-License-Identifier: Apache-2.0
diff --git a/cuda_core/docs/source/_templates/autosummary/cyclass.rst b/cuda_core/docs/source/_templates/autosummary/cyclass.rst
index 81d045a6b0a..99b74ca0658 100644
--- a/cuda_core/docs/source/_templates/autosummary/cyclass.rst
+++ b/cuda_core/docs/source/_templates/autosummary/cyclass.rst
@@ -1,4 +1,4 @@
-.. SPDX-FileCopyrightText: Copyright (c) 2024-2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+.. SPDX-FileCopyrightText: Copyright (c) 2024-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
 .. SPDX-License-Identifier: Apache-2.0
 
 {{ fullname | escape | underline}}
diff --git a/cuda_core/docs/source/release.rst b/cuda_core/docs/source/release.rst
index f7c9f19c776..b8726b4d661 100644
--- a/cuda_core/docs/source/release.rst
+++ b/cuda_core/docs/source/release.rst
@@ -1,4 +1,4 @@
-.. SPDX-FileCopyrightText: Copyright (c) 2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+.. SPDX-FileCopyrightText: Copyright (c) 2025-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
 .. SPDX-License-Identifier: Apache-2.0
 
 Release Notes
diff --git a/cuda_core/docs/source/release/0.3.0-notes.rst b/cuda_core/docs/source/release/0.3.0-notes.rst
index d59f912743d..057664a56ff 100644
--- a/cuda_core/docs/source/release/0.3.0-notes.rst
+++ b/cuda_core/docs/source/release/0.3.0-notes.rst
@@ -1,4 +1,4 @@
-.. SPDX-FileCopyrightText: Copyright (c) 2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+.. SPDX-FileCopyrightText: Copyright (c) 2025-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
 .. SPDX-License-Identifier: Apache-2.0
 
 .. currentmodule:: cuda.core.experimental
diff --git a/cuda_core/docs/source/release/0.4.0-notes.rst b/cuda_core/docs/source/release/0.4.0-notes.rst
index cbe3d432400..f7d69dc5d58 100644
--- a/cuda_core/docs/source/release/0.4.0-notes.rst
+++ b/cuda_core/docs/source/release/0.4.0-notes.rst
@@ -1,4 +1,4 @@
-.. SPDX-FileCopyrightText: Copyright (c) 2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+.. SPDX-FileCopyrightText: Copyright (c) 2025-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
 .. SPDX-License-Identifier: Apache-2.0
 
 .. currentmodule:: cuda.core.experimental
diff --git a/cuda_core/docs/source/release/0.5.1-notes.rst b/cuda_core/docs/source/release/0.5.1-notes.rst
index a52b88d1380..538b838a3ca 100644
--- a/cuda_core/docs/source/release/0.5.1-notes.rst
+++ b/cuda_core/docs/source/release/0.5.1-notes.rst
@@ -1,4 +1,4 @@
-.. SPDX-FileCopyrightText: Copyright (c) 2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+.. SPDX-FileCopyrightText: Copyright (c) 2025-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
 .. SPDX-License-Identifier: Apache-2.0
 
 .. currentmodule:: cuda.core
diff --git a/cuda_core/tests/cython/build_tests.sh b/cuda_core/tests/cython/build_tests.sh
index 7ee65c50d68..72403baf571 100755
--- a/cuda_core/tests/cython/build_tests.sh
+++ b/cuda_core/tests/cython/build_tests.sh
@@ -1,7 +1,7 @@
 #!/bin/bash
 set -eo pipefail
 
-# SPDX-FileCopyrightText: Copyright (c) 2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+# SPDX-FileCopyrightText: Copyright (c) 2025-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
 # SPDX-License-Identifier: Apache-2.0
 
 UNAME=$(uname)
diff --git a/cuda_core/tests/helpers/layout.py b/cuda_core/tests/helpers/layout.py
index e4102f4d45a..3e2aa6d2241 100644
--- a/cuda_core/tests/helpers/layout.py
+++ b/cuda_core/tests/helpers/layout.py
@@ -1,4 +1,4 @@
-# SPDX-FileCopyrightText: Copyright (c) 2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+# SPDX-FileCopyrightText: Copyright (c) 2025-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
 #
 # SPDX-License-Identifier: Apache-2.0
 
diff --git a/cuda_core/tests/test_context.py b/cuda_core/tests/test_context.py
index 66f7582ea7e..53182520e24 100644
--- a/cuda_core/tests/test_context.py
+++ b/cuda_core/tests/test_context.py
@@ -1,4 +1,4 @@
-# SPDX-FileCopyrightText: Copyright (c) 2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+# SPDX-FileCopyrightText: Copyright (c) 2025-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
 # SPDX-License-Identifier: Apache-2.0
 
 import pytest
diff --git a/cuda_core/tests/test_memory.py b/cuda_core/tests/test_memory.py
index a2afff99469..7eb92608d1c 100644
--- a/cuda_core/tests/test_memory.py
+++ b/cuda_core/tests/test_memory.py
@@ -2946,6 +2946,7 @@ def test_mempool_watermark_reset(memory_resource_factory, kind):
         mr.close()
 
 
+@pytest.mark.thread_unsafe(reason="CUDA legacy-default-stream mempool teardown/sync race (gh-3350)")
 @pytest.mark.agent_authored(model="claude-opus-5-5")
 def test_mempool_trim(memory_resource_factory):
     device = Device()
diff --git a/cuda_pathfinder/cuda/pathfinder/_utils/env_vars.py b/cuda_pathfinder/cuda/pathfinder/_utils/env_vars.py
index 12198ac9f7f..b8c3267d541 100644
--- a/cuda_pathfinder/cuda/pathfinder/_utils/env_vars.py
+++ b/cuda_pathfinder/cuda/pathfinder/_utils/env_vars.py
@@ -1,4 +1,4 @@
-# SPDX-FileCopyrightText: Copyright (c) 2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+# SPDX-FileCopyrightText: Copyright (c) 2025-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
 # SPDX-License-Identifier: Apache-2.0
 
 """Centralized CUDA environment variable handling.
diff --git a/cuda_pathfinder/cuda/pathfinder/_utils/find_sub_dirs.py b/cuda_pathfinder/cuda/pathfinder/_utils/find_sub_dirs.py
index ebb7b13f488..55705ba6393 100644
--- a/cuda_pathfinder/cuda/pathfinder/_utils/find_sub_dirs.py
+++ b/cuda_pathfinder/cuda/pathfinder/_utils/find_sub_dirs.py
@@ -1,4 +1,4 @@
-# SPDX-FileCopyrightText: Copyright (c) 2024-2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+# SPDX-FileCopyrightText: Copyright (c) 2024-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
 # SPDX-License-Identifier: Apache-2.0
 
 import functools
diff --git a/cuda_pathfinder/cuda/pathfinder/_utils/platform_aware.py b/cuda_pathfinder/cuda/pathfinder/_utils/platform_aware.py
index af0610a6cdb..be55b6ff9c3 100644
--- a/cuda_pathfinder/cuda/pathfinder/_utils/platform_aware.py
+++ b/cuda_pathfinder/cuda/pathfinder/_utils/platform_aware.py
@@ -1,4 +1,4 @@
-# SPDX-FileCopyrightText: Copyright (c) 2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+# SPDX-FileCopyrightText: Copyright (c) 2025-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
 # SPDX-License-Identifier: Apache-2.0
 
 import sys
diff --git a/cuda_pathfinder/tests/conftest.py b/cuda_pathfinder/tests/conftest.py
index e8a5e11b391..d88e22b1959 100644
--- a/cuda_pathfinder/tests/conftest.py
+++ b/cuda_pathfinder/tests/conftest.py
@@ -1,4 +1,4 @@
-# SPDX-FileCopyrightText: Copyright (c) 2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+# SPDX-FileCopyrightText: Copyright (c) 2025-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
 # SPDX-License-Identifier: Apache-2.0
 
 
diff --git a/cuda_pathfinder/tests/test_utils_env_vars.py b/cuda_pathfinder/tests/test_utils_env_vars.py
index 99a55324fc0..e675f243b4a 100644
--- a/cuda_pathfinder/tests/test_utils_env_vars.py
+++ b/cuda_pathfinder/tests/test_utils_env_vars.py
@@ -1,4 +1,4 @@
-# SPDX-FileCopyrightText: Copyright (c) 2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+# SPDX-FileCopyrightText: Copyright (c) 2025-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
 # SPDX-License-Identifier: Apache-2.0
 
 import os
diff --git a/cuda_pathfinder/tests/test_utils_find_sub_dirs.py b/cuda_pathfinder/tests/test_utils_find_sub_dirs.py
index 56dab23dc42..7714e898649 100644
--- a/cuda_pathfinder/tests/test_utils_find_sub_dirs.py
+++ b/cuda_pathfinder/tests/test_utils_find_sub_dirs.py
@@ -1,4 +1,4 @@
-# SPDX-FileCopyrightText: Copyright (c) 2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+# SPDX-FileCopyrightText: Copyright (c) 2025-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
 # SPDX-License-Identifier: Apache-2.0
 
 from pathlib import Path
diff --git a/toolshed/check_spdx.py b/toolshed/check_spdx.py
index 1be8a565db7..03733ba533f 100644
--- a/toolshed/check_spdx.py
+++ b/toolshed/check_spdx.py
@@ -71,14 +71,24 @@ def load_spdx_ignore():
 CURRENT_YEAR = str(datetime.datetime.now(tz=datetime.UTC).year)
 
 
-def is_staged(filepath):
-    # If the file is staged, we need to update it to the current year
-    process = subprocess.run(  # noqa: S603
-        ["git", "diff", "--staged", "--", filepath],  # noqa: S607
+def last_modified_year(filepath):
+    # Staged or unstaged working-tree changes mean the file is being modified now.
+    status = subprocess.run(  # noqa: S603
+        ["git", "status", "--porcelain", "--", filepath],  # noqa: S607
         capture_output=True,
         text=True,
     )
-    return process.stdout.strip() != ""
+    if status.stdout.strip():
+        return int(CURRENT_YEAR)
+    # Use the last commit's UTC year, matching the year for working-tree changes.
+    log = subprocess.run(  # noqa: S603
+        ["git", "log", "-1", "--no-show-signature", "--format=%ct", "--", filepath],  # noqa: S607
+        capture_output=True,
+        text=True,
+    )
+    timestamp = log.stdout.strip()
+    # Fall back to current year for brand-new untracked files with no git history.
+    return datetime.datetime.fromtimestamp(int(timestamp), tz=datetime.UTC).year if timestamp else int(CURRENT_YEAR)
 
 
 def normalize_repo_path(filepath):
@@ -165,13 +175,15 @@ def validate_or_fix_copyright(filepath, blob, fix):
     else:
         start_year = end_year = years
 
-    if not is_staged(filepath) or int(end_year) >= int(CURRENT_YEAR):
+    if int(end_year) >= last_modified_year(filepath):
         return True, blob
 
     print(f"OUTDATED copyright {years!r} (expected {CURRENT_YEAR!r}) in {filepath!r}")
     if not fix:
         return False, blob
 
+    # Always write the current year: committing the fix is itself a change made
+    # this year, so an older year would be stale again immediately.
     new_years = f"{start_year}-{CURRENT_YEAR}"
     return (
         False,