diff --git a/tests/fix_byte_order_marker_test.py b/tests/fix_byte_order_marker_test.py
new file mode 100644
index 0000000..da150e3
--- /dev/null
+++ b/tests/fix_byte_order_marker_test.py
@@ -0,0 +1,13 @@
+from pre_commit_hooks import fix_byte_order_marker
+
+
+def test_failure(tmpdir):
+    f = tmpdir.join('f.txt')
+    f.write_text('ohai', encoding='utf-8-sig')
+    assert fix_byte_order_marker.main((str(f),)) == 1
+
+
+def test_success(tmpdir):
+    f = tmpdir.join('f.txt')
+    f.write_text('ohai', encoding='utf-8')
+    assert fix_byte_order_marker.main((str(f),)) == 0