diff --git a/analytical_engine/apps/clustering/clustering.h b/analytical_engine/apps/clustering/clustering.h
index 3efcfaa69fe2..742c9014edf9 100644
--- a/analytical_engine/apps/clustering/clustering.h
+++ b/analytical_engine/apps/clustering/clustering.h
@@ -16,7 +16,6 @@ limitations under the License.
 #ifndef ANALYTICAL_ENGINE_APPS_CLUSTERING_CLUSTERING_H_
 #define ANALYTICAL_ENGINE_APPS_CLUSTERING_CLUSTERING_H_
 
-#include <iostream>
 #include <unordered_map>
 #include <utility>
 #include <vector>
diff --git a/python/graphscope/nx/tests/test_ctx_builtin.py b/python/graphscope/nx/tests/test_ctx_builtin.py
index fef070699165..b7526b29aed4 100644
--- a/python/graphscope/nx/tests/test_ctx_builtin.py
+++ b/python/graphscope/nx/tests/test_ctx_builtin.py
@@ -244,6 +244,8 @@ def test_hits(self):
     def test_clustering(self):
         ans = nx.builtin.clustering(self.p2p)
         self.assert_result_almost_equal(ans, self.p2p_clus_ans)
+
+    def test_clustering_undirected(self):
         # test undirected graph
         G = nx.Graph()
         G.add_nodes_from([1, 2, 3])