diff --git a/cpp/src/sampling/neighbor_sampling_impl.hpp b/cpp/src/sampling/neighbor_sampling_impl.hpp
index b0e78ec7db..2df150fb76 100644
--- a/cpp/src/sampling/neighbor_sampling_impl.hpp
+++ b/cpp/src/sampling/neighbor_sampling_impl.hpp
@@ -334,9 +334,10 @@ neighbor_sample_impl(raft::handle_t const& handle,
         starting_vertex_labels,
         raft::device_span<vertex_t const>{level_result_dst_vectors.back().data(),
                                           level_result_dst_vectors.back().size()},
-        frontier_vertex_labels ? std::make_optional(raft::device_span<label_t const>(
-                                   level_result_label_vectors->back().data(), level_result_label_vectors->back().size()))
-                               : std::nullopt,
+        frontier_vertex_labels
+          ? std::make_optional(raft::device_span<label_t const>(
+              level_result_label_vectors->back().data(), level_result_label_vectors->back().size()))
+          : std::nullopt,
         std::move(vertex_used_as_source),
         modified_graph_view.local_vertex_partition_view(),
         vertex_partition_range_lasts,