diff --git a/include/small_gicp/ann/kdtree_omp.hpp b/include/small_gicp/ann/kdtree_omp.hpp
index c8fa6ae..89f7b2b 100644
--- a/include/small_gicp/ann/kdtree_omp.hpp
+++ b/include/small_gicp/ann/kdtree_omp.hpp
@@ -25,7 +25,7 @@ struct KdTreeBuilderOMP {
 
 #pragma omp parallel num_threads(num_threads)
     {
-#pragma omp single
+#pragma omp single nowait
       {
         //
         kdtree.root = create_node(kdtree, node_count, points, kdtree.indices.begin(), kdtree.indices.begin(), kdtree.indices.end());