diff --git a/tests/test_labeling.py b/tests/test_labeling.py
index 9a5d9bc1d..d65cab60f 100644
--- a/tests/test_labeling.py
+++ b/tests/test_labeling.py
@@ -275,7 +275,11 @@ def test_label_communities_batches_when_over_batch_size(monkeypatch):
         return "{" + ", ".join(f'"{c}": "Cluster {c}"' for c in cids) + "}"
 
     monkeypatch.setattr("graphify.llm._call_llm", fake_call)
-    labels = label_communities(G, communities, backend="gemini", batch_size=100)
+    # max_concurrency=1 keeps the batches sequential so `calls` records them in a
+    # deterministic order; the default concurrent path can complete them out of
+    # order (the ordering is asserted separately in
+    # test_label_communities_parallel_matches_sequential).
+    labels = label_communities(G, communities, backend="gemini", batch_size=100, max_concurrency=1)
 
     # 250 communities / 100 per batch -> 3 batches (100, 100, 50)
     assert calls == [100, 100, 50]