diff --git a/src/asio_client_session_impl.cc b/src/asio_client_session_impl.cc
index b96824dd..1d5ab925 100644
--- a/src/asio_client_session_impl.cc
+++ b/src/asio_client_session_impl.cc
@@ -577,7 +577,7 @@ const request *session_impl::submit(boost::system::error_code &ec,
 }
 
 void session_impl::shutdown() {
-  if (stopped_) {
+  if (session_ == nullptr || stopped_) {
     return;
   }