diff --git a/README.md b/README.md
index 522fff7..3d09b7e 100644
--- a/README.md
+++ b/README.md
@@ -82,7 +82,8 @@ By default, a warning (`pyproject_metadata.errors.ExtraKeyWarning`) will be
 issued for extra fields at the project table. You can pass `allow_extra_keys=`
 to either avoid the check (`True`) or hard error (`False`). If you want to
 detect extra keys, you can get them with `pyproject_metadata.extra_top_level`
-and `pyproject_metadata.extra_build_sytem`.
+and `pyproject_metadata.extra_build_system`. It is recommended that build
+systems only warn on failures with these extra keys.
 
 ## Validating classifiers
 
diff --git a/pyproject_metadata/__init__.py b/pyproject_metadata/__init__.py
index a624468..bac3d16 100644
--- a/pyproject_metadata/__init__.py
+++ b/pyproject_metadata/__init__.py
@@ -586,6 +586,12 @@ def _write_metadata(  # noqa: C901
         if self.license_files is not None:
             for license_file in sorted(set(self.license_files)):
                 smart_message["License-File"] = os.fspath(license_file.as_posix())
+        elif (
+            self.auto_metadata_version not in constants.PRE_SPDX_METADATA_VERSIONS
+            and isinstance(self.license, License)
+            and self.license.file
+        ):
+            smart_message["License-File"] = os.fspath(self.license.file.as_posix())
 
         for classifier in self.classifiers:
             smart_message["Classifier"] = classifier
diff --git a/tests/packages/fulltext_license/LICENSE.txt b/tests/packages/fulltext_license/LICENSE.txt
new file mode 100644
index 0000000..c3713cd
--- /dev/null
+++ b/tests/packages/fulltext_license/LICENSE.txt
@@ -0,0 +1,20 @@
+Copyright © 2019 Filipe Laíns <filipe.lains@gmail.com>
+
+Permission is hereby granted, free of charge, to any person obtaining a
+copy of this software and associated documentation files (the "Software"),
+to deal in the Software without restriction, including without limitation
+the rights to use, copy, modify, merge, publish, distribute, sublicense,
+and/or sell copies of the Software, and to permit persons to whom the
+Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice (including the next
+paragraph) shall be included in all copies or substantial portions of the
+Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+DEALINGS IN THE SOFTWARE.
diff --git a/tests/test_standard_metadata.py b/tests/test_standard_metadata.py
index 7bb93f6..ccd1c91 100644
--- a/tests/test_standard_metadata.py
+++ b/tests/test_standard_metadata.py
@@ -2,6 +2,7 @@
 
 from __future__ import annotations
 
+import contextlib
 import pathlib
 import re
 import shutil
@@ -19,6 +20,7 @@
     import tomllib
 
 import pyproject_metadata
+import pyproject_metadata.constants
 
 DIR = pathlib.Path(__file__).parent.resolve()
 
@@ -29,6 +31,11 @@
     exceptiongroup = None  # type: ignore[assignment]
 
 
+@pytest.fixture(params=pyproject_metadata.constants.KNOWN_METADATA_VERSIONS)
+def metadata_version(request: pytest.FixtureRequest) -> str:
+    return request.param  # type: ignore[no-any-return]
+
+
 @pytest.fixture(params=["one_error", "all_errors", "exceptiongroup"])
 def all_errors(request: pytest.FixtureRequest, monkeypatch: pytest.MonkeyPatch) -> bool:
     param: str = request.param
@@ -1245,6 +1252,30 @@ def test_as_rfc822_spdx_empty_glob(
                 )
 
 
+def test_license_file_24(
+    metadata_version: str, monkeypatch: pytest.MonkeyPatch
+) -> None:
+    monkeypatch.chdir(DIR / "packages/fulltext_license")
+    with contextlib.nullcontext() if metadata_version in pyproject_metadata.constants.PRE_SPDX_METADATA_VERSIONS else pytest.warns(
+        pyproject_metadata.errors.ConfigurationWarning
+    ):
+        metadata = pyproject_metadata.StandardMetadata.from_pyproject(
+            {
+                "project": {
+                    "name": "fulltext_license",
+                    "version": "0.1.0",
+                    "license": {"file": "LICENSE.txt"},
+                },
+            },
+            metadata_version=metadata_version,
+        )
+    message = str(metadata.as_rfc822())
+    if metadata_version in pyproject_metadata.constants.PRE_SPDX_METADATA_VERSIONS:
+        assert "License-File: LICENSE.txt" not in message
+    else:
+        assert "License-File: LICENSE.txt" in message
+
+
 def test_as_rfc822_dynamic(monkeypatch: pytest.MonkeyPatch) -> None:
     monkeypatch.chdir(DIR / "packages/dynamic-description")
 
@@ -1260,7 +1291,6 @@ def test_as_rfc822_dynamic(monkeypatch: pytest.MonkeyPatch) -> None:
     ]
 
 
-@pytest.mark.parametrize("metadata_version", ["2.1", "2.2", "2.3"])
 def test_as_rfc822_set_metadata(metadata_version: str) -> None:
     metadata = pyproject_metadata.StandardMetadata.from_pyproject(
         {