diff --git a/test/run/test_exports.py b/test/run/test_exports.py
new file mode 100644
index 00000000..12b4cfe7
--- /dev/null
+++ b/test/run/test_exports.py
@@ -0,0 +1,89 @@
+import contextlib
+import json
+import os
+import pathlib
+import shutil
+import subprocess
+
+import pytest
+
+from .. import test
+
+
+@pytest.fixture(name="jsondata", scope="module")
+def jsondata_fixture():
+    return json.dumps({
+        "version": "2",
+        "pipelines": [
+            {
+                "name": "image",
+                "stages": [
+                    {
+                        "type": "org.osbuild.truncate",
+                        "options": {
+                            "filename": "foo.img",
+                            "size": "10",
+                        },
+                    },
+                    {
+                        # cannot use org.osbuild.chown as it needs the chown
+                        # binary in the stage
+                        "type": "org.osbuild.testing.injectpy",
+                        "options": {
+                            "code": [
+                                'import os',
+                                'os.chown(f"{tree}/foo.img", 1000, 1000)',
+                            ],
+                        },
+                    },
+                ]
+            }
+        ]
+    })
+
+
+@pytest.fixture(name="osb", scope="module")
+def osbuild_fixture():
+    with test.OSBuild() as osb:
+        yield osb
+
+
+@pytest.fixture(name="testing_libdir", scope="module")
+def testing_libdir_fixture(tmpdir_factory):
+    tests_path = pathlib.Path(__file__).parent.parent
+    project_path = tests_path.parent
+    testing_libdir_path = tests_path / "stages"
+    fake_libdir_path = tmpdir_factory.mktemp("fake-libdir")
+    # there must be an empty "osbild" dir for a "os.listdir(self._libdir)"
+    # in buildroot.py
+    (fake_libdir_path / "osbuild").mkdir()
+    # construct minimal viable libdir from current checkout
+    for d in ["stages", "runners", ]:
+        subprocess.run(
+            ["cp", "-a", os.fspath(project_path / d), f"{fake_libdir_path}"],
+            check=True)
+    # now inject testing stages
+    for p in testing_libdir_path.glob("org.osbuild.testing.*"):
+        shutil.copy2(p, fake_libdir_path / "stages")
+    yield fake_libdir_path
+
+
+@pytest.mark.skipif(os.getuid() != 0, reason="root-only")
+def test_exports_normal(osb, tmp_path, jsondata, testing_libdir):  # pylint: disable=unused-argument
+    osb.compile(jsondata, output_dir=tmp_path, exports=["image"], libdir=testing_libdir)
+    expected_export = tmp_path / "image/foo.img"
+    assert expected_export.exists()
+    assert expected_export.stat().st_uid == 1000
+
+
+@pytest.mark.skipif(os.getuid() != 0, reason="root-only")
+def test_exports_with_force_no_preserve_owner(osb, tmp_path, jsondata, testing_libdir):
+    with contextlib.ExitStack() as cm:
+        k = "OSBUILD_EXPORT_FORCE_NO_PRESERVE_OWNER"
+        os.environ[k] = "1"
+        cm.callback(os.unsetenv, k)
+
+        osb.compile(jsondata, output_dir=tmp_path, exports=["image"], libdir=testing_libdir)
+        expected_export = tmp_path / "image/foo.img"
+        assert expected_export.exists()
+        assert expected_export.stat().st_uid == 0
diff --git a/test/stages/README.md b/test/stages/README.md
new file mode 100644
index 00000000..1000bff9
--- /dev/null
+++ b/test/stages/README.md
@@ -0,0 +1,5 @@
+This directory contains stages that can only be used during testing and
+will be dynamically added to the library directory.
+
+See `test/run/test_exports.py` for an example usage of the `pyinject`
+stage.
diff --git a/test/stages/org.osbuild.testing.injectpy b/test/stages/org.osbuild.testing.injectpy
new file mode 100755
index 00000000..b842a8e7
--- /dev/null
+++ b/test/stages/org.osbuild.testing.injectpy
@@ -0,0 +1,27 @@
+#!/usr/bin/python3
+"""
+Inject arbitrary python code.
+
+ONLY USE FOR TESTING
+"""
+
+import sys
+
+import osbuild.api
+
+SCHEMA_2 = """
+"options": {
+  "additionalProperties": true
+}
+"""
+
+
+def main(tree, options):  # pylint: disable=unused-argument
+    script = "\n".join(options.get("code", []))
+    exec(script)  # pylint: disable=exec-used
+
+
+if __name__ == '__main__':
+    args = osbuild.api.arguments()
+    r = main(args["tree"], args.get("options", {}))
+    sys.exit(r)
diff --git a/test/test.py b/test/test.py
index b9602e58..018bc4e0 100644
--- a/test/test.py
+++ b/test/test.py
@@ -347,7 +347,7 @@ class OSBuild(contextlib.AbstractContextManager):
             print(log)
         print("-- END ---------------------------------")
 
-    def compile(self, data_stdin, output_dir=None, checkpoints=None, check=False, exports=None):
+    def compile(self, data_stdin, output_dir=None, checkpoints=None, check=False, exports=None, libdir="."):
         """Compile an Artifact
 
         This takes a manifest as `data_stdin`, executes the pipeline, and
@@ -377,7 +377,7 @@ class OSBuild(contextlib.AbstractContextManager):
             cmd_args = [sys.executable, "-m", "osbuild"]
 
             cmd_args += ["--json"]
-            cmd_args += ["--libdir", "."]
+            cmd_args += ["--libdir", libdir]
             cmd_args += ["--output-directory", output_dir]
             cmd_args += ["--store", self._cachedir]