diff --git a/rclcpp/src/rclcpp/context.cpp b/rclcpp/src/rclcpp/context.cpp
index 90ea3db908..7e4c28da1c 100644
--- a/rclcpp/src/rclcpp/context.cpp
+++ b/rclcpp/src/rclcpp/context.cpp
@@ -344,6 +344,7 @@ Context::shutdown(const std::string & reason)
 rclcpp::Context::OnShutdownCallback
 Context::on_shutdown(OnShutdownCallback callback)
 {
+  std::lock_guard<std::mutex> lock(on_shutdown_callbacks_mutex_);
   on_shutdown_callbacks_.push_back(callback);
   return callback;
 }