diff --git a/sql/sql_manager.cc b/sql/sql_manager.cc
index 5cd66d8047a..a286497235e 100644
--- a/sql/sql_manager.cc
+++ b/sql/sql_manager.cc
@@ -26,6 +26,10 @@
 #include "sql_manager.h"
 #include "sql_base.h"                           // flush_tables
 
+/*
+  Values for manager_thread_in_use: 0 means "not started". 1 means "started
+  and active". 2 means "stopped".
+*/
 static bool volatile manager_thread_in_use = 0;
 static bool abort_manager = false;
 
@@ -44,7 +48,7 @@ static struct handler_cb *cb_list; // protected by LOCK_manager
 bool mysql_manager_submit(void (*action)(void *), void *data)
 {
   bool result= FALSE;
-  DBUG_ASSERT(manager_thread_in_use);
+  DBUG_ASSERT(manager_thread_in_use == 1);
   struct handler_cb **cb;
   mysql_mutex_lock(&LOCK_manager);
   cb= &cb_list;
@@ -119,7 +123,7 @@ pthread_handler_t handle_manager(void *arg __attribute__((unused)))
     mysql_mutex_lock(&LOCK_manager);
   }
   DBUG_ASSERT(cb_list == NULL);
-  manager_thread_in_use = 0;
+  manager_thread_in_use = 2;
   mysql_mutex_unlock(&LOCK_manager);
   mysql_mutex_destroy(&LOCK_manager);
   mysql_cond_destroy(&COND_manager);
@@ -148,6 +152,15 @@ void start_handle_manager()
     }
 
     mysql_mutex_lock(&LOCK_manager);
+    /*
+      Wait for manager thread to have started, otherwise in extreme cases the
+      server may start up and have initiated shutdown at the time the manager
+      thread even starts to run.
+
+      Allow both values 1 and 2 for manager_thread_in_use, so that we will not
+      get stuck here if the manager thread somehow manages to start up and
+      abort again before we have time to test it here.
+    */
     while (!manager_thread_in_use)
       mysql_cond_wait(&COND_manager, &LOCK_manager);
     mysql_mutex_unlock(&LOCK_manager);