diff --git a/libraries/plugins/peerplays_sidechain/include/graphene/peerplays_sidechain/sidechain_net_handler.hpp b/libraries/plugins/peerplays_sidechain/include/graphene/peerplays_sidechain/sidechain_net_handler.hpp
index 3aa4465c..a9257e54 100644
--- a/libraries/plugins/peerplays_sidechain/include/graphene/peerplays_sidechain/sidechain_net_handler.hpp
+++ b/libraries/plugins/peerplays_sidechain/include/graphene/peerplays_sidechain/sidechain_net_handler.hpp
@@ -1,5 +1,6 @@
 #pragma once
 
+#include <mutex>
 #include <vector>
 
 #include <boost/program_options.hpp>
@@ -60,6 +61,7 @@ protected:
    std::map<std::string, std::string> private_keys;
 
    std::vector<std::string> son_listener_log;
+   std::mutex son_listener_log_mutex;
 
    void on_applied_block(const signed_block &b);
 
diff --git a/libraries/plugins/peerplays_sidechain/sidechain_net_handler.cpp b/libraries/plugins/peerplays_sidechain/sidechain_net_handler.cpp
index 45fab4ee..7c87a9ef 100644
--- a/libraries/plugins/peerplays_sidechain/sidechain_net_handler.cpp
+++ b/libraries/plugins/peerplays_sidechain/sidechain_net_handler.cpp
@@ -619,13 +619,15 @@ void sidechain_net_handler::settle_sidechain_transactions() {
 }
 
 void sidechain_net_handler::add_to_son_listener_log(std::string trx_id) {
+   const std::lock_guard<std::mutex> lock(son_listener_log_mutex);
    son_listener_log.insert(son_listener_log.begin(), trx_id);
    if (son_listener_log.size() > 33) {
-      son_listener_log.erase(son_listener_log.end());
+      son_listener_log.pop_back();
    }
 }
 
 std::vector<std::string> sidechain_net_handler::get_son_listener_log() {
+   const std::lock_guard<std::mutex> lock(son_listener_log_mutex);
    return son_listener_log;
 }