diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index f8b9e1d..fe484c7 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -44,6 +44,13 @@ jobs:
       - name: Run
         run: tox
 
+      - name: Upload coverage
+        uses: actions/upload-artifact@v4
+        with:
+          name: coverage-${{ matrix.python }}
+          path: .coverage.*
+          if-no-files-found: ignore
+
   ruff:
     name: "Ruff ${{ matrix.python }} on ${{ matrix.platform }}"
     runs-on: "${{ matrix.platform }}"
@@ -75,3 +82,46 @@ jobs:
 
       - name: Run
         run: tox -e lint
+
+  coverage:
+    name: Coverage report
+    runs-on: ubuntu-latest
+    needs: test
+
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: 3.12
+          cache: pip
+          cache-dependency-path: |
+            **/pyproject.toml
+            **/tox.ini
+
+      - name: Download coverage data
+        uses: actions/download-artifact@v4
+        with:
+          pattern: coverage-*
+          merge-multiple: true
+
+      - name: Install dependencies
+        run: |
+          python -m pip install --upgrade pip
+          python -m pip install coverage[toml]
+
+      - name: Coverage report
+        run: |
+          coverage combine
+          coverage html
+          coverage report --format=markdown >> $GITHUB_STEP_SUMMARY
+          coverage report --fail-under=70
+
+      - name: Upload report
+        uses: actions/upload-artifact@v4
+        with:
+          path: htmlcov
+          name: htmlcov
diff --git a/pyproject.toml b/pyproject.toml
index 254a3d6..fb1fe1a 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -36,6 +36,7 @@ dependencies = [
 [project.optional-dependencies]
 test = [
     "pytest",
+    "coverage[toml]",
 ]
 
 [project.urls]
@@ -44,6 +45,34 @@ Repository = "https://github.com/python-wheel-build/elfdeps"
 [project.scripts]
 elfdeps = "elfdeps.__main__:main"
 
+[tool.coverage.run]
+branch = true
+parallel = true
+relative_files = true
+source = [
+    "elfdeps",
+    "tests/",
+]
+
+[tool.coverage.paths]
+source = [
+   "src/elfdeps",
+   ".tox/py*/**/site-packages/elfdeps",
+]
+tests =[
+   "tests/",
+]
+
+[tool.coverage.report]
+show_missing = true
+skip_covered = true
+exclude_lines = [
+    "pragma: no cover",
+    "@abc.abstractmethod",
+    "@typing.overload",
+    "if typing.TYPE_CHECKING",
+]
+
 [tool.setuptools_scm]
 # do not include +gREV local version, required for Test PyPI upload
 local_scheme = "no-local-version"
diff --git a/src/elfdeps/__main__.py b/src/elfdeps/__main__.py
index 42b0b78..408cd3d 100644
--- a/src/elfdeps/__main__.py
+++ b/src/elfdeps/__main__.py
@@ -9,8 +9,8 @@
 
 from . import _archives, _elfdeps
 
-ZIPEXT = frozenset({".zip", ".whl"})
-TAREXT = frozenset({".tar", ".tar.gz", ".tgz", ".tar.bz2", "tbz2", "tar.xz", "txz"})
+ZIPEXT = (".zip", ".whl")
+TAREXT = (".tar", ".tar.gz", ".tgz", ".tar.bz2", ".tbz2", ".tar.xz", ".txz")
 
 parser = argparse.ArgumentParser("elfdeps")
 parser.add_argument("filename", type=pathlib.Path)
@@ -89,9 +89,9 @@ def main(argv: list[str] | None = None) -> None:
         unique=args.unique,
     )
     filename: pathlib.Path = args.filename
-    if filename.suffix in ZIPEXT:
+    if filename.name.endswith(ZIPEXT):
         infos = list(zip_requires(filename, settings=settings))
-    elif filename.suffix in TAREXT:
+    elif filename.name.endswith(TAREXT):
         infos = list(tar_requires(filename, settings=settings))
     else:
         infos = [_elfdeps.analyze_file(filename, settings=settings)]
diff --git a/tests/test_main.py b/tests/test_main.py
new file mode 100644
index 0000000..5e83e5a
--- /dev/null
+++ b/tests/test_main.py
@@ -0,0 +1,33 @@
+import pathlib
+import subprocess
+import sys
+import tarfile
+import zipfile
+
+
+def test_main_binary() -> None:
+    python = pathlib.Path(sys.executable).resolve()
+    out = subprocess.check_output(["elfdeps", python], text=True)
+    assert str(python) in out
+
+
+def test_main_tarfile(tmp_path: pathlib.Path):
+    tname = tmp_path / "test.tar.gz"
+    python = pathlib.Path(sys.executable).resolve()
+    with tarfile.TarFile.open(tname, mode="w:gz") as tf:
+        # FIXME: remove '.so' suffix
+        tf.add(python, "python-binary.so")
+        tf.add(__file__, "test.py")
+    out = subprocess.check_output(["elfdeps", str(tname)], text=True)
+    assert "python-binary" in out
+
+
+def test_main_zipfile(tmp_path: pathlib.Path) -> None:
+    zname = tmp_path / "test.zip"
+    python = pathlib.Path(sys.executable).resolve()
+    with zipfile.ZipFile(zname, mode="w") as zf:
+        # FIXME: remove '.so' suffix
+        zf.write(python, "python-binary.so")
+        zf.write(__file__, "test.py")
+    out = subprocess.check_output(["elfdeps", str(zname)], text=True)
+    assert "python-binary" in out
diff --git a/tox.ini b/tox.ini
index c832bc3..6295337 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,14 +1,29 @@
 # SPDX-License-Identifier: Apache-2.0
 
 [tox]
-envlist=py3{10,11,12},lint
+envlist=py3{10,11,12},lint,coverage-report
 
 [testenv]
 package = wheel
 wheel_build_env = pkg
 extras = test
+set_env =
+    COVERAGE_PROCESS_START={toxinidir}/pyproject.toml
+commands_pre =
+    py3{10,11,12}: {envpython} -c 'import pathlib; pathlib.Path("{env_site_packages_dir}/cov.pth").write_text("import coverage; coverage.process_startup()")'
 commands =
-    python -m pytest tests
+    coverage run -m pytest {posargs:tests}
+
+[testenv:coverage-report]
+description = Report coverage over all test runs.
+basepython = py312
+depends = py3{10,11,12}
+deps = coverage[toml]
+skip_install = true
+parallel_show_output = true
+commands =
+    coverage combine
+    coverage report
 
 [testenv:lint]
 basepython = python3