diff --git a/mysql-test/r/timezone_grant.result b/mysql-test/r/timezone_grant.result
index 685f8007ac7..471cacde300 100644
--- a/mysql-test/r/timezone_grant.result
+++ b/mysql-test/r/timezone_grant.result
@@ -45,6 +45,13 @@ select * from mysql.time_zone_name;
 ERROR 42000: SELECT command denied to user 'mysqltest_1'@'localhost' for table 'time_zone_name'
 select Name, convert_tz('2004-11-30 12:00:00', Name, 'UTC') from mysql.time_zone_name;
 ERROR 42000: SELECT command denied to user 'mysqltest_1'@'localhost' for table 'time_zone_name'
+drop table t1, t2;
+create table t1 (a int, b datetime);
+create table t2 (a int, b varchar(40));
+update t1 set b = '2005-01-01 10:00';
+update t1 set b = convert_tz(b, 'UTC', 'UTC');
+update t1 join t2 on (t1.a = t2.a) set t1.b = '2005-01-01 10:00' where t2.b = 'foo';
+update t1 join t2 on (t1.a = t2.a) set t1.b = convert_tz('2005-01-01 10:00','UTC','UTC') where t2.b = 'foo';
 delete from mysql.user where user like 'mysqltest\_%';
 delete from mysql.db where user like 'mysqltest\_%';
 delete from mysql.tables_priv where user like 'mysqltest\_%';
diff --git a/mysql-test/t/timezone_grant.test b/mysql-test/t/timezone_grant.test
index 501315668f5..8627866a0bf 100644
--- a/mysql-test/t/timezone_grant.test
+++ b/mysql-test/t/timezone_grant.test
@@ -61,6 +61,18 @@ select * from mysql.time_zone_name;
 --error 1142
 select Name, convert_tz('2004-11-30 12:00:00', Name, 'UTC') from mysql.time_zone_name;
 
+#
+# Bug #9979: Use of CONVERT_TZ in multiple-table UPDATE causes bogus
+# privilege error
+#
+drop table t1, t2;
+create table t1 (a int, b datetime);
+create table t2 (a int, b varchar(40));
+update t1 set b = '2005-01-01 10:00';
+update t1 set b = convert_tz(b, 'UTC', 'UTC');
+update t1 join t2 on (t1.a = t2.a) set t1.b = '2005-01-01 10:00' where t2.b = 'foo';
+update t1 join t2 on (t1.a = t2.a) set t1.b = convert_tz('2005-01-01 10:00','UTC','UTC') where t2.b = 'foo';
+
 # Clean-up
 connection default;
 delete from mysql.user where user like 'mysqltest\_%';
diff --git a/sql/sql_parse.cc b/sql/sql_parse.cc
index f0ea0a762bd..a515441ee1b 100644
--- a/sql/sql_parse.cc
+++ b/sql/sql_parse.cc
@@ -1938,7 +1938,8 @@ mysql_execute_command(THD *thd)
     that is not a SHOW command or a select that only access local
     variables, but for now this is probably good enough.
   */
-  if (tables || &lex->select_lex != lex->all_selects_list)
+  if (tables || &lex->select_lex != lex->all_selects_list ||
+      lex->time_zone_tables_used)
     mysql_reset_errors(thd);
 
 #ifdef HAVE_REPLICATION
@@ -5354,7 +5355,7 @@ int multi_update_precheck(THD *thd, TABLE_LIST *tables)
   /*
     Is there tables of subqueries?
   */
-  if (&lex->select_lex != lex->all_selects_list)
+  if (&lex->select_lex != lex->all_selects_list || lex->time_zone_tables_used)
   {
     DBUG_PRINT("info",("Checking sub query list"));
     for (table= tables; table; table= table->next)