diff --git a/tests/test_read.py b/tests/test_read.py
index 33fdfbc..ee8b8c9 100644
--- a/tests/test_read.py
+++ b/tests/test_read.py
@@ -230,7 +230,7 @@ def test_read_uullg_table(
 
 @pytest.mark.unittest
 def test_read_gef_cpts(data_dir):
-    files = Path(data_dir / "cpt").glob("*.gef")
+    files = sorted(Path(data_dir / "cpt").glob("*.gef"))
     cpts = read_gef_cpts(files)
     assert isinstance(cpts, CptCollection)