diff --git a/mysql-test/suite/rpl/r/rpl_alter_online_debug.result b/mysql-test/suite/rpl/r/rpl_alter_online_debug.result
new file mode 100644
index 00000000000..49329d2261b
--- /dev/null
+++ b/mysql-test/suite/rpl/r/rpl_alter_online_debug.result
@@ -0,0 +1,39 @@
+include/master-slave.inc
+[connection master]
+connection slave;
+include/stop_slave.inc
+set global slave_parallel_threads=3;
+set global slave_parallel_mode= optimistic;
+connection master;
+#
+# MDEV-31755 Replica's DML event deadlocks wit online alter table
+#
+# Three threads for SA,U,CA
+create table t (id int, a int, primary key (id)) engine=innodb;
+insert into t values (1,10), (2,20);
+set @@session.binlog_alter_two_phase=1;
+set debug_sync= 'alter_table_online_downgraded signal ready wait_for go';
+alter table t add c text default('qqq') after id, algorithm=copy, lock=none;
+connection master1;
+set debug_sync= 'now wait_for ready';
+update t set a = 1;
+set debug_sync= 'now signal go';
+connection master;
+include/save_master_gtid.inc
+connection slave;
+include/start_slave.inc
+include/sync_with_master_gtid.inc
+select * from t;
+id	c	a
+1	qqq	1
+2	qqq	1
+connection master;
+drop table t;
+connection slave;
+connection master;
+connection slave;
+include/stop_slave.inc
+set global slave_parallel_threads=0;
+set global slave_parallel_mode=   optimistic;
+include/start_slave.inc
+include/rpl_end.inc
diff --git a/mysql-test/suite/rpl/t/rpl_alter_online_debug.test b/mysql-test/suite/rpl/t/rpl_alter_online_debug.test
new file mode 100644
index 00000000000..a038b4a3934
--- /dev/null
+++ b/mysql-test/suite/rpl/t/rpl_alter_online_debug.test
@@ -0,0 +1,59 @@
+source include/have_debug_sync.inc;
+source include/have_innodb.inc;
+source include/master-slave.inc;
+
+
+--connection slave
+source include/stop_slave.inc;
+--let $slave_parallel_threads=`select @@global.slave_parallel_threads`
+--let $slave_parallel_mode=   `select @@global.slave_parallel_mode`
+set global slave_parallel_threads=3;
+set global slave_parallel_mode= optimistic;
+--connection master
+
+
+--echo #
+--echo # MDEV-31755 Replica's DML event deadlocks wit online alter table
+--echo #
+--echo # Three threads for SA,U,CA
+
+create table t (id int, a int, primary key (id)) engine=innodb;
+insert into t values (1,10), (2,20);
+
+set @@session.binlog_alter_two_phase=1;
+set debug_sync= 'alter_table_online_downgraded signal ready wait_for go';
+send alter table t add c text default('qqq') after id, algorithm=copy, lock=none;
+
+--connection master1
+set debug_sync= 'now wait_for ready';
+
+update t set a = 1;
+
+set debug_sync= 'now signal go';
+
+--connection master
+--reap
+--source include/save_master_gtid.inc
+
+--connection slave
+source include/start_slave.inc;
+--source include/sync_with_master_gtid.inc
+select * from t;
+
+# Cleanup
+--connection master
+drop table t;
+--sync_slave_with_master
+--connection master
+
+--echo #
+--echo # End of 11.2 tests
+--echo #
+
+--connection slave
+source include/stop_slave.inc;
+--eval set global slave_parallel_threads=$slave_parallel_threads
+--eval set global slave_parallel_mode=   $slave_parallel_mode
+source include/start_slave.inc;
+
+--source include/rpl_end.inc
diff --git a/sql/sql_table.cc b/sql/sql_table.cc
index fd9ab9468bb..a08d0edcfbd 100644
--- a/sql/sql_table.cc
+++ b/sql/sql_table.cc
@@ -86,7 +86,7 @@ static int copy_data_between_tables(THD *, TABLE *,TABLE *,
                                     List<Create_field> &, bool, uint, ORDER *,
                                     ha_rows *, ha_rows *,
                                     Alter_info::enum_enable_or_disable,
-                                    Alter_table_ctx *, bool);
+                                    Alter_table_ctx *, bool, uint64);
 static int append_system_key_parts(THD *thd, HA_CREATE_INFO *create_info,
                                    Key *key);
 static int mysql_prepare_create_table(THD *, HA_CREATE_INFO *, Alter_info *,
@@ -11140,7 +11140,7 @@ do_continue:;
                                  alter_info->create_list, ignore,
                                  order_num, order, &copied, &deleted,
                                  alter_info->keys_onoff,
-                                 &alter_ctx, online))
+                                 &alter_ctx, online, start_alter_id))
       goto err_new_table_cleanup;
   }
   else
@@ -11696,7 +11696,8 @@ copy_data_between_tables(THD *thd, TABLE *from, TABLE *to,
                          uint order_num, ORDER *order,
                          ha_rows *copied, ha_rows *deleted,
                          Alter_info::enum_enable_or_disable keys_onoff,
-                         Alter_table_ctx *alter_ctx, bool online)
+                         Alter_table_ctx *alter_ctx, bool online,
+                         uint64 start_alter_id)
 {
   int error= 1;
   Copy_field *copy= NULL, *copy_end;
@@ -12104,6 +12105,14 @@ copy_data_between_tables(THD *thd, TABLE *from, TABLE *to,
     thd->lock= NULL;
 
     error= online_alter_read_from_binlog(thd, &rgi, binlog);
+    if (start_alter_id)
+    {
+      DBUG_ASSERT(thd->slave_thread);
+
+      int rpl_error= wait_for_master(thd);
+      if (rpl_error)
+        error= 1;
+    }
 
     DEBUG_SYNC(thd, "alter_table_online_before_lock");