diff --git a/pre_commit/commands/run.py b/pre_commit/commands/run.py
index 98ae25dc..a0725660 100644
--- a/pre_commit/commands/run.py
+++ b/pre_commit/commands/run.py
@@ -38,14 +38,14 @@ def _hook_msg_start(hook, verbose):
 
 def _filter_by_include_exclude(filenames, include, exclude):
     include_re, exclude_re = re.compile(include), re.compile(exclude)
-    return {
+    return [
         filename for filename in filenames
         if (
             include_re.search(filename) and
             not exclude_re.search(filename) and
             os.path.lexists(filename)
         )
-    }
+    ]
 
 
 def _filter_by_types(filenames, types, exclude_types):
diff --git a/tests/commands/run_test.py b/tests/commands/run_test.py
index cd32c5f6..91e84d98 100644
--- a/tests/commands/run_test.py
+++ b/tests/commands/run_test.py
@@ -770,19 +770,19 @@ def test_fail_fast(
 def some_filenames():
     return (
         '.pre-commit-hooks.yaml',
-        'pre_commit/main.py',
-        'pre_commit/git.py',
         'im_a_file_that_doesnt_exist.py',
+        'pre_commit/git.py',
+        'pre_commit/main.py',
     )
 
 
 def test_include_exclude_base_case(some_filenames):
     ret = _filter_by_include_exclude(some_filenames, '', '^$')
-    assert ret == {
+    assert ret == [
         '.pre-commit-hooks.yaml',
-        'pre_commit/main.py',
         'pre_commit/git.py',
-    }
+        'pre_commit/main.py',
+    ]
 
 
 @xfailif_no_symlink
@@ -790,19 +790,19 @@ def test_matches_broken_symlink(tmpdir):  # pragma: no cover (non-windows)
     with tmpdir.as_cwd():
         os.symlink('does-not-exist', 'link')
         ret = _filter_by_include_exclude({'link'}, '', '^$')
-        assert ret == {'link'}
+        assert ret == ['link']
 
 
 def test_include_exclude_total_match(some_filenames):
     ret = _filter_by_include_exclude(some_filenames, r'^.*\.py$', '^$')
-    assert ret == {'pre_commit/main.py', 'pre_commit/git.py'}
+    assert ret == ['pre_commit/git.py', 'pre_commit/main.py']
 
 
 def test_include_exclude_does_search_instead_of_match(some_filenames):
     ret = _filter_by_include_exclude(some_filenames, r'\.yaml$', '^$')
-    assert ret == {'.pre-commit-hooks.yaml'}
+    assert ret == ['.pre-commit-hooks.yaml']
 
 
 def test_include_exclude_exclude_removes_files(some_filenames):
     ret = _filter_by_include_exclude(some_filenames, '', r'\.py$')
-    assert ret == {'.pre-commit-hooks.yaml'}
+    assert ret == ['.pre-commit-hooks.yaml']