diff --git a/tests/cli_test.py b/tests/cli_test.py
new file mode 100644
index 0000000..6829cd5
--- /dev/null
+++ b/tests/cli_test.py
@@ -0,0 +1,71 @@
+import sys
+import subprocess
+from pathlib import Path
+
+import pytest
+
+DIR = Path(__file__).resolve().parent
+
+expected = """\
+/*
+  This file contains docstrings for use in the Python bindings.
+  Do not edit! They were automatically extracted by pybind11_mkdoc.
+ */
+
+#define MKD_EXPAND(x)                                      x
+#define MKD_COUNT(_1, _2, _3, _4, _5, _6, _7, COUNT, ...)  COUNT
+#define MKD_VA_SIZE(...)                                   MKD_EXPAND(MKD_COUNT(__VA_ARGS__, 7, 6, 5, 4, 3, 2, 1, 0))
+#define MKD_CAT1(a, b)                                     a ## b
+#define MKD_CAT2(a, b)                                     MKD_CAT1(a, b)
+#define MKD_DOC1(n1)                                       mkd_doc_##n1
+#define MKD_DOC2(n1, n2)                                   mkd_doc_##n1##_##n2
+#define MKD_DOC3(n1, n2, n3)                               mkd_doc_##n1##_##n2##_##n3
+#define MKD_DOC4(n1, n2, n3, n4)                           mkd_doc_##n1##_##n2##_##n3##_##n4
+#define MKD_DOC5(n1, n2, n3, n4, n5)                       mkd_doc_##n1##_##n2##_##n3##_##n4##_##n5
+#define MKD_DOC7(n1, n2, n3, n4, n5, n6, n7)               mkd_doc_##n1##_##n2##_##n3##_##n4##_##n5##_##n6##_##n7
+#define DOC(...)                                           MKD_EXPAND(MKD_EXPAND(MKD_CAT2(MKD_DOC, MKD_VA_SIZE(__VA_ARGS__)))(__VA_ARGS__))
+
+#if defined(__GNUG__)
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wunused-variable"
+#endif
+
+
+static const char *mkd_doc_RootLevelSymbol =
+R"doc(Root-level symbol. Magna fermentum iaculis eu non diam phasellus
+vestibulum.)doc";
+
+static const char *mkd_doc_drake_MidLevelSymbol =
+R"doc(1. Begin first ordered list element. Rutrum quisque non tellus orci ac
+auctor. End first ordered list element. 2. Begin second ordered list
+element. Ipsum faucibus vitae aliquet nec. Ligula ullamcorper
+malesuada proin libero. End second ordered list element. 3. Begin
+third ordered list element. Dictum sit amet justo donec enim. Pharetra
+convallis posuere morbi leo urna molestie. End third ordered list
+element.
+
+Senectus et netus et malesuada fames ac. Tincidunt lobortis feugiat
+vivamus at augue eget arcu dictum varius.)doc";
+
+#if defined(__GNUG__)
+#pragma GCC diagnostic pop
+#endif
+
+"""
+
+
+@pytest.mark.parametrize(
+    "name",
+    ["sample_header.h", "sample header with spaces.h"],
+    ids=["no_spaces", "spaces"],
+)
+def test_simple_header_cli(tmp_path: Path, name: str) -> None:
+    # Run pybind11-mkdoc and put the output in a temp file
+    tf = tmp_path / "tmp.h"
+    header = DIR / "sample_header_docs" / name
+    subprocess.run([sys.executable, "-m", "pybind11_mkdoc", "-o", tf, header], check=True)
+
+    # Ensure the header file matches
+    res = tf.read_text(encoding="utf-8")
+
+    assert res == expected
diff --git a/tests/sample_header_docs/sample header with spaces.h b/tests/sample_header_docs/sample header with spaces.h
new file mode 120000
index 0000000..48dbf9b
--- /dev/null
+++ b/tests/sample_header_docs/sample header with spaces.h	
@@ -0,0 +1 @@
+sample_header.h
\ No newline at end of file