diff --git a/src/pipautocompile/io.py b/src/pipautocompile/io.py
index 21aaac7..bec2223 100644
--- a/src/pipautocompile/io.py
+++ b/src/pipautocompile/io.py
@@ -6,7 +6,6 @@
 
 if TYPE_CHECKING:
     from re import RegexFlag
-    from typing import Iterable
     from typing import Iterator
 
     from _typeshed import StrOrBytesPath
@@ -32,11 +31,7 @@ def file_contains_pattern(
     return False
 
 
-def find_spec_files(
-    path: StrPath = ".",
-    patterns: Iterable[str] = ("**/requirements.in", "**/requirements/*.in"),
-) -> Iterator[Path]:
-    for pattern in patterns:
-        for spec in Path(path).glob(pattern):
-            if spec.is_file():
-                yield spec
+def find_spec_files(pattern: str, path: StrPath = ".") -> Iterator[Path]:
+    for spec in Path(path).glob(pattern):
+        if spec.is_file():
+            yield spec
diff --git a/src/pipautocompile/main.py b/src/pipautocompile/main.py
index 8aefb6f..8c1cefe 100644
--- a/src/pipautocompile/main.py
+++ b/src/pipautocompile/main.py
@@ -48,11 +48,19 @@
     default="--allow-unsafe --generate-hashes --no-reuse-hashes --upgrade",
     show_default=True,
 )
+@click.option(
+    "--spec-pattern",
+    help="Glob pattern to match spec files; may be used more than once.",
+    multiple=True,
+    default=("**/requirements.in", "**/requirements/*.in"),
+    show_default=True,
+)
 def cli(
     docker_build_stage: str,
     docker_ssh_agent_passthrough: bool,
     git_recurse_submodules: bool,
     pip_compile_args_str: str,
+    spec_pattern: tuple[str],
 ) -> None:
     """Automate pip-compile for multiple environments."""
 
@@ -61,7 +69,8 @@ def cli(
         "CUSTOM_COMPILE_COMMAND": quote_args("pip-autocompile", *sys.argv[1:])
     }
 
-    for spec_dir, specs in groupby(sorted(find_spec_files()), key=lambda s: s.parent):
+    spec_files = sorted({f for p in spec_pattern for f in find_spec_files(p)})
+    for spec_dir, specs in groupby(spec_files, key=lambda s: s.parent):
         if not git_recurse_submodules and inside_submodule(spec_dir):
             continue
 
diff --git a/tests/test_io.py b/tests/test_io.py
index 54f25a8..2c8d292 100644
--- a/tests/test_io.py
+++ b/tests/test_io.py
@@ -1,15 +1,11 @@
 from __future__ import annotations
 
 from pathlib import Path
-from typing import TYPE_CHECKING
 
 import pytest
 
 from pipautocompile.io import find_spec_files
 
-if TYPE_CHECKING:
-    from typing import Any
-
 
 @pytest.fixture
 def spec_tree(tmp_path: Path) -> Path:
@@ -33,64 +29,43 @@ def spec_tree(tmp_path: Path) -> Path:
     return tmp_path
 
 
-@pytest.fixture(params=(True, False), ids=("relative", "absolute"))
-def spec_root(request: pytest.FixtureRequest, spec_tree: Path) -> Path:
-    if request.param:  # type: ignore[attr-defined]
-        request.getfixturevalue("monkeypatch").chdir(spec_tree)
-        return Path()
-    else:
-        return spec_tree
-
-
+@pytest.mark.parametrize("chdir", (True, False), ids=("relative", "absolute"))
 @pytest.mark.parametrize(
-    argnames=("kwargs", "expected_specs"),
+    argnames=("pattern", "expected_specs"),
     argvalues=(
-        pytest.param(
-            {},
-            {
-                "nested/requirements/foo.in",
-                "nested/requirements/bar.in",
-                "nested/requirements.in",
-                "requirements/50_base.in",
-                "requirements/60_dev.in",
-                "requirements/61_prod.in",
-                "requirements.in",
-            },
-            id="default patterns",
+        (
+            "*.spec",
+            set(),
         ),
-        pytest.param(
-            {"patterns": {"requirements.in"}},
+        (
+            "requirements.in",
             {
                 "requirements.in",
             },
-            id="requirements.in",
         ),
-        pytest.param(
-            {"patterns": {"requirements/*.in"}},
+        (
+            "requirements/*.in",
             {
                 "requirements/50_base.in",
                 "requirements/60_dev.in",
                 "requirements/61_prod.in",
             },
-            id="requirements/*.in",
         ),
-        pytest.param(
-            {"patterns": {"*/requirements.in"}},
+        (
+            "*/requirements.in",
             {
                 "nested/requirements.in",
             },
-            id="*/requirements.in",
         ),
-        pytest.param(
-            {"patterns": {"**/requirements.in"}},
+        (
+            "**/requirements.in",
             {
                 "requirements.in",
                 "nested/requirements.in",
             },
-            id="**/requirements.in",
         ),
-        pytest.param(
-            {"patterns": {"**/requirements/*.in"}},
+        (
+            "**/requirements/*.in",
             {
                 "nested/requirements/foo.in",
                 "nested/requirements/bar.in",
@@ -98,35 +73,26 @@ def spec_root(request: pytest.FixtureRequest, spec_tree: Path) -> Path:
                 "requirements/60_dev.in",
                 "requirements/61_prod.in",
             },
-            id="**/requirements/*.in",
         ),
-        pytest.param(
-            {"patterns": {"**/requirements/*.spec"}},
+        (
+            "**/requirements/*.spec",
             {
                 "requirements/50_base.spec",
                 "requirements/60_dev.spec",
                 "requirements/61_prod.spec",
             },
-            id="**/requirements/*.spec",
-        ),
-        pytest.param(
-            {"patterns": {"**/requirements/*.in", "**/requirements/*.spec"}},
-            {
-                "nested/requirements/foo.in",
-                "nested/requirements/bar.in",
-                "requirements/50_base.in",
-                "requirements/60_dev.in",
-                "requirements/61_prod.in",
-                "requirements/50_base.spec",
-                "requirements/60_dev.spec",
-                "requirements/61_prod.spec",
-            },
-            id="**/requirements/*.(in|spec)",
         ),
     ),
 )
 def test_find_spec_files(
-    spec_root: Path, kwargs: dict[str, Any], expected_specs: set[str]
+    request: pytest.FixtureRequest,
+    spec_tree: Path,
+    chdir: bool,
+    pattern: str,
+    expected_specs: set[str],
 ) -> None:
-    rooted_specs = {spec_root / spec for spec in expected_specs}
-    assert set(find_spec_files(spec_root, **kwargs)) == rooted_specs
+    if chdir:
+        request.getfixturevalue("monkeypatch").chdir(spec_tree)
+        spec_tree = Path()
+    rooted_specs = {spec_tree / spec for spec in expected_specs}
+    assert set(find_spec_files(pattern, path=spec_tree)) == rooted_specs