diff --git a/examples/asio-sv.cc b/examples/asio-sv.cc
index 88bebec3..f942eef8 100644
--- a/examples/asio-sv.cc
+++ b/examples/asio-sv.cc
@@ -42,13 +42,6 @@
 using namespace nghttp2::asio_http2;
 using namespace nghttp2::asio_http2::server;
 
-void all_threads_created_cb(
-    std::vector<std::shared_ptr<thread_info>> all_threads_info) {
-  for (auto thread_info : all_threads_info) {
-    std::cout << "thread pid: " << thread_info->pid << std::endl;
-  }
-}
-
 int main(int argc, char *argv[]) {
   try {
     // Check command line arguments.
@@ -69,7 +62,12 @@ int main(int argc, char *argv[]) {
 
     server.num_threads(num_threads);
 
-    server.set_on_all_threads_created_callback(all_threads_created_cb);
+    server.set_on_all_threads_created_callback(
+        [](const auto &all_threads_info) {
+          for (auto &thread_info : all_threads_info) {
+            std::cout << "thread pid: " << thread_info->pid << std::endl;
+          }
+        });
 
     server.handle("/", [](const request &req, const response &res) {
       res.write_head(200, {{"foo", {"bar"}}});
diff --git a/src/asio_server.cc b/src/asio_server.cc
index 996a9986..bedb5e22 100644
--- a/src/asio_server.cc
+++ b/src/asio_server.cc
@@ -71,7 +71,7 @@ server::listen_and_serve(boost::system::error_code &ec,
     }
   }
 
-  io_service_pool_.run(asynchronous, all_threads_created_cb);
+  io_service_pool_.run(asynchronous, std::move(all_threads_created_cb));
 
   return ec;
 }
diff --git a/src/asio_server_http2_impl.cc b/src/asio_server_http2_impl.cc
index 2e1a6ad1..f0ecf71f 100644
--- a/src/asio_server_http2_impl.cc
+++ b/src/asio_server_http2_impl.cc
@@ -59,7 +59,7 @@ void http2_impl::backlog(int backlog) { backlog_ = backlog; }
 
 void http2_impl::set_on_all_threads_created_callback(
     on_all_threads_created_cb cb) {
-  all_threads_created_cb_ = cb;
+  all_threads_created_cb_ = std::move(cb);
 }
 
 void http2_impl::tls_handshake_timeout(