diff --git a/mysql-test/main/mdl_sync.result b/mysql-test/main/mdl_sync.result
index ae36a65aab4..9abeb05b011 100644
--- a/mysql-test/main/mdl_sync.result
+++ b/mysql-test/main/mdl_sync.result
@@ -2433,6 +2433,9 @@ create table t1 (a int) engine=myisam;
 create table t2 (a int) stats_persistent=0, engine=innodb;
 insert into t1 values (1);
 insert into t2 values (1);
+connect  con1, localhost, root;
+start transaction with consistent snapshot;
+connection default;
 SET DEBUG_SYNC= 'after_open_table_mdl_shared SIGNAL table_opened WAIT_FOR grlwait execute 2';
 update t1,t2 set t1.a=2,t2.a=3;
 connection con2;
@@ -2464,6 +2467,7 @@ connection default;
 SET DEBUG_SYNC= 'RESET';
 drop table t1,t2;
 disconnect con2;
+disconnect con1;
 #
 # Bug#50786 Assertion `thd->mdl_context.trans_sentinel() == __null' 
 #           failed in open_ltable()
diff --git a/mysql-test/main/mdl_sync.test b/mysql-test/main/mdl_sync.test
index 8ce4d1eb2b5..40a1112a6d4 100644
--- a/mysql-test/main/mdl_sync.test
+++ b/mysql-test/main/mdl_sync.test
@@ -3117,6 +3117,12 @@ create table t2 (a int) stats_persistent=0, engine=innodb;
 insert into t1 values (1);
 insert into t2 values (1);
 
+connect (con1, localhost, root);
+# disable innodb purge thread, otherwise it might start purging t2,
+# and will take an mdl, affecting metadata_lock_info output.
+start transaction with consistent snapshot;
+connection default;
+
 SET DEBUG_SYNC= 'after_open_table_mdl_shared SIGNAL table_opened WAIT_FOR grlwait execute 2';
 --send update t1,t2 set t1.a=2,t2.a=3
 
@@ -3162,6 +3168,7 @@ connection default;
 SET DEBUG_SYNC= 'RESET';
 drop table t1,t2;
 disconnect con2;
+disconnect con1;
 
 --echo #
 --echo # Bug#50786 Assertion `thd->mdl_context.trans_sentinel() == __null'