diff --git a/src/ansys/dpf/composites/_composite_model_impl.py b/src/ansys/dpf/composites/_composite_model_impl.py
index 2d57f4302..84c9557c3 100644
--- a/src/ansys/dpf/composites/_composite_model_impl.py
+++ b/src/ansys/dpf/composites/_composite_model_impl.py
@@ -154,9 +154,11 @@ def material_names(self) -> Dict[str, int]:
         try:
             helper_op = dpf.Operator("composite::materials_container_helper")
         except Exception as exc:
-            raise RuntimeError(f"Operator composite::materials_container_helper doesn't exist. "
-                               f"This could be because the server version is 2024 R1-pre0. Please use "
-                               f"the latest preview or the unified installer. Error: {exc}") from exc
+            raise RuntimeError(
+                f"Operator composite::materials_container_helper doesn't exist. "
+                f"This could be because the server version is 2024 R1-pre0. Please use "
+                f"the latest preview or the unified installer. Error: {exc}"
+            ) from exc
 
         helper_op.inputs.materials_container(self._material_operators.material_provider.outputs)
         string_field = helper_op.outputs.material_names()
diff --git a/tests/composite_model_test.py b/tests/composite_model_test.py
index 585980c2d..4f3ee4668 100644
--- a/tests/composite_model_test.py
+++ b/tests/composite_model_test.py
@@ -83,16 +83,16 @@ def test_basic_functionality_of_composite_model(dpf_server, data_files, distribu
 
     assert [ply["id"] for ply in sampling_point.analysis_plies] == analysis_ply_ids
 
-    ref_material_names = {
-        "Epoxy Carbon UD (230 GPa) Prepreg": 3,
-        "Epoxy Carbon Woven (230 GPa) Wet": 2,
-        "Honeycomb": 4,
-        "Structural Steel": 1,
-    }
+    ref_material_names = [
+        "Epoxy Carbon UD (230 GPa) Prepreg",
+        "Epoxy Carbon Woven (230 GPa) Wet",
+        "Honeycomb",
+        "Structural Steel",
+    ]
     mat_names = composite_model.material_names
     assert len(mat_names) == len(ref_material_names)
-    for mat_name, dpf_mat_id in ref_material_names.items():
-        assert mat_names[mat_name] == dpf_mat_id
+    for mat_name in ref_material_names:
+        assert mat_name in mat_names.keys()
 
     timer.add("After getting properties")