diff --git a/sql/wsrep_var.cc b/sql/wsrep_var.cc
index dea388d30de..239daadc4f6 100644
--- a/sql/wsrep_var.cc
+++ b/sql/wsrep_var.cc
@@ -674,7 +674,11 @@ static void wsrep_slave_count_change_update ()
 
 bool wsrep_slave_threads_update (sys_var *self, THD* thd, enum_var_type type)
 {
+  mysql_mutex_unlock(&LOCK_wsrep_cluster_config);
+  mysql_mutex_unlock(&LOCK_global_system_variables);
   mysql_mutex_lock(&LOCK_wsrep_slave_threads);
+  mysql_mutex_lock(&LOCK_global_system_variables);
+  mysql_mutex_lock(&LOCK_wsrep_cluster_config);
   bool res= false;
 
   wsrep_slave_count_change_update();