diff --git a/cpp/tests/cluster/kmeans_balanced.cu b/cpp/tests/cluster/kmeans_balanced.cu
index f1e12e09dc..10d4ce9cbb 100644
--- a/cpp/tests/cluster/kmeans_balanced.cu
+++ b/cpp/tests/cluster/kmeans_balanced.cu
@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: Copyright (c) 2022-2026, NVIDIA CORPORATION.
+ * SPDX-FileCopyrightText: Copyright (c) 2022-2026, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
  * SPDX-License-Identifier: Apache-2.0
  */
 
@@ -45,7 +45,7 @@ template <typename MathT, typename IdxT>
 ::std::ostream& operator<<(::std::ostream& os, const KmeansBalancedInputs<MathT, IdxT>& p)
 {
   os << "{ " << p.n_rows << ", " << p.n_cols << ", " << p.n_clusters << ", " << p.kb_params.n_iters
-     << static_cast<int>(p.kb_params.metric) << '}' << std::endl;
+     << static_cast<int>(p.kb_params.metric) << '}';
   return os;
 }
 
diff --git a/cpp/tests/neighbors/all_neighbors.cuh b/cpp/tests/neighbors/all_neighbors.cuh
index 3b6b245a4e..7201ebfb4e 100644
--- a/cpp/tests/neighbors/all_neighbors.cuh
+++ b/cpp/tests/neighbors/all_neighbors.cuh
@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: Copyright (c) 2025, NVIDIA CORPORATION.
+ * SPDX-FileCopyrightText: Copyright (c) 2025-2026, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
  * SPDX-License-Identifier: Apache-2.0
  */
 #pragma once
@@ -51,7 +51,7 @@ inline ::std::ostream& operator<<(::std::ostream& os, const AllNeighborsInputs&
   os << "dataset shape=" << p.n_rows << "x" << p.dim << ", k=" << p.k
      << ", metric=" << static_cast<int>(std::get<1>(p.build_algo_metric_recall))
      << ", clusters=" << std::get<0>(p.cluster_nearestcluster)
-     << ", overlap_factor=" << std::get<1>(p.cluster_nearestcluster) << std::endl;
+     << ", overlap_factor=" << std::get<1>(p.cluster_nearestcluster);
   return os;
 }
 
diff --git a/cpp/tests/neighbors/ann_brute_force.cuh b/cpp/tests/neighbors/ann_brute_force.cuh
index 7f18b59483..62152f71d3 100644
--- a/cpp/tests/neighbors/ann_brute_force.cuh
+++ b/cpp/tests/neighbors/ann_brute_force.cuh
@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: Copyright (c) 2023-2024, NVIDIA CORPORATION.
+ * SPDX-FileCopyrightText: Copyright (c) 2023-2026, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
  * SPDX-License-Identifier: Apache-2.0
  */
 #pragma once
@@ -32,7 +32,7 @@ template <typename T, typename IdxT>
 ::std::ostream& operator<<(::std::ostream& os, const AnnBruteForceInputs<IdxT>& p)
 {
   os << "{ " << p.num_queries << ", " << p.num_db_vecs << ", " << p.dim << ", " << p.k << ", "
-     << static_cast<int>(p.metric) << static_cast<T>(p.metric_arg) << '}' << std::endl;
+     << static_cast<int>(p.metric) << static_cast<T>(p.metric_arg) << '}';
   return os;
 }
 
diff --git a/cpp/tests/neighbors/ann_cagra.cuh b/cpp/tests/neighbors/ann_cagra.cuh
index 7b86cc70ad..79bf339827 100644
--- a/cpp/tests/neighbors/ann_cagra.cuh
+++ b/cpp/tests/neighbors/ann_cagra.cuh
@@ -322,7 +322,7 @@ inline ::std::ostream& operator<<(::std::ostream& os, const AnnCagraInputs& p)
     os << ", pq_bits=" << vpq.pq_bits << ", pq_dim=" << vpq.pq_dim
        << ", vq_n_centers=" << vpq.vq_n_centers << ", smem_dtype=" << smem_dtype_str(p.smem_dtype);
   }
-  os << '}' << std::endl;
+  os << '}';
   return os;
 }
 
diff --git a/cpp/tests/neighbors/ann_ivf_flat.cuh b/cpp/tests/neighbors/ann_ivf_flat.cuh
index ccd7e2a253..5eb540ef6c 100644
--- a/cpp/tests/neighbors/ann_ivf_flat.cuh
+++ b/cpp/tests/neighbors/ann_ivf_flat.cuh
@@ -49,7 +49,7 @@ template <typename IdxT>
      << p.nprobe << ", " << p.nlist << ", "
      << cuvs::neighbors::print_metric{static_cast<cuvs::distance::DistanceType>((int)p.metric)}
      << ", " << p.adaptive_centers << "," << p.host_dataset << "," << p.kernel_copy_overlapping
-     << '}' << std::endl;
+     << '}';
   return os;
 }
 
diff --git a/cpp/tests/neighbors/ann_ivf_sq.cuh b/cpp/tests/neighbors/ann_ivf_sq.cuh
index 969be22771..6b97ec6eea 100644
--- a/cpp/tests/neighbors/ann_ivf_sq.cuh
+++ b/cpp/tests/neighbors/ann_ivf_sq.cuh
@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: Copyright (c) 2026, NVIDIA CORPORATION.
+ * SPDX-FileCopyrightText: Copyright (c) 2026, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
  * SPDX-License-Identifier: Apache-2.0
  */
 #pragma once
@@ -42,7 +42,7 @@ template <typename IdxT>
   os << "{ " << p.num_queries << ", " << p.num_db_vecs << ", " << p.dim << ", " << p.k << ", "
      << p.nprobe << ", " << p.nlist << ", "
      << cuvs::neighbors::print_metric{static_cast<cuvs::distance::DistanceType>((int)p.metric)}
-     << ", " << (p.host_dataset ? "host" : "device") << '}' << std::endl;
+     << ", " << (p.host_dataset ? "host" : "device") << '}';
   return os;
 }
 
diff --git a/cpp/tests/neighbors/ann_nn_descent.cuh b/cpp/tests/neighbors/ann_nn_descent.cuh
index 568cebbc23..a4474a9382 100644
--- a/cpp/tests/neighbors/ann_nn_descent.cuh
+++ b/cpp/tests/neighbors/ann_nn_descent.cuh
@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: Copyright (c) 2023-2026, NVIDIA CORPORATION.
+ * SPDX-FileCopyrightText: Copyright (c) 2023-2026, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
  * SPDX-License-Identifier: Apache-2.0
  */
 #pragma once
@@ -50,8 +50,7 @@ struct AnnNNDescentBatchInputs {
 inline ::std::ostream& operator<<(::std::ostream& os, const AnnNNDescentInputs& p)
 {
   os << "dataset shape=" << p.n_rows << "x" << p.dim << ", graph_degree=" << p.graph_degree
-     << ", metric=" << static_cast<int>(p.metric) << (p.host_dataset ? ", host" : ", device")
-     << std::endl;
+     << ", metric=" << static_cast<int>(p.metric) << (p.host_dataset ? ", host" : ", device");
   return os;
 }
 
@@ -59,7 +58,7 @@ inline ::std::ostream& operator<<(::std::ostream& os, const AnnNNDescentBatchInp
 {
   os << "dataset shape=" << p.n_rows << "x" << p.dim << ", graph_degree=" << p.graph_degree
      << ", metric=" << static_cast<int>(p.metric) << (p.host_dataset ? ", host" : ", device")
-     << ", clusters=" << p.recall_cluster.second << std::endl;
+     << ", clusters=" << p.recall_cluster.second;
   return os;
 }
 
diff --git a/cpp/tests/neighbors/dynamic_batching.cuh b/cpp/tests/neighbors/dynamic_batching.cuh
index 9f54325b7a..22f710121f 100644
--- a/cpp/tests/neighbors/dynamic_batching.cuh
+++ b/cpp/tests/neighbors/dynamic_batching.cuh
@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: Copyright (c) 2024-2025, NVIDIA CORPORATION.
+ * SPDX-FileCopyrightText: Copyright (c) 2024-2026, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
  * SPDX-License-Identifier: Apache-2.0
  */
 #pragma once
@@ -43,7 +43,7 @@ inline ::std::ostream& operator<<(::std::ostream& os, const dynamic_batching_spe
   os << ", max_batch_size=" << p.max_batch_size;
   os << ", n_queues=" << p.n_queues;
   os << ", conservative_dispatch=" << p.conservative_dispatch;
-  os << '}' << std::endl;
+  os << '}';
   return os;
 }
 
diff --git a/cpp/tests/neighbors/hnsw.cu b/cpp/tests/neighbors/hnsw.cu
index 28238c17bf..a92deaf725 100644
--- a/cpp/tests/neighbors/hnsw.cu
+++ b/cpp/tests/neighbors/hnsw.cu
@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: Copyright (c) 2023-2024, NVIDIA CORPORATION.
+ * SPDX-FileCopyrightText: Copyright (c) 2023-2026, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
  * SPDX-License-Identifier: Apache-2.0
  */
 
@@ -39,7 +39,7 @@ inline ::std::ostream& operator<<(::std::ostream& os, const AnnHNSWInputs& p)
   os << "dataset shape=" << p.n_rows << "x" << p.dim << ", graph_degree=" << p.graph_degree
      << ", metric="
      << cuvs::neighbors::print_metric{static_cast<cuvs::distance::DistanceType>((int)p.metric)}
-     << ", ef=" << (p.ef) << std::endl;
+     << ", ef=" << (p.ef);
   return os;
 }
 
diff --git a/cpp/tests/neighbors/tiered_index.cu b/cpp/tests/neighbors/tiered_index.cu
index 38d0126e03..f342c44a2b 100644
--- a/cpp/tests/neighbors/tiered_index.cu
+++ b/cpp/tests/neighbors/tiered_index.cu
@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: Copyright (c) 2025, NVIDIA CORPORATION.
+ * SPDX-FileCopyrightText: Copyright (c) 2025-2026, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
  * SPDX-License-Identifier: Apache-2.0
  */
 
@@ -46,8 +46,7 @@ inline ::std::ostream& operator<<(::std::ostream& os, const TieredIndexTestStrat
 inline ::std::ostream& operator<<(::std::ostream& os, const AnnTieredIndexInputs& p)
 {
   os << "dataset shape=" << p.n_rows << "x" << p.dim << ", metric=" << print_metric{p.metric}
-     << ", k=" << p.k << ", n_queries=" << p.n_queries << ", test_strategy=" << p.test_strategy
-     << std::endl;
+     << ", k=" << p.k << ", n_queries=" << p.n_queries << ", test_strategy=" << p.test_strategy;
   return os;
 }