diff --git a/mysql-test/r/ps.result b/mysql-test/r/ps.result
index 84d705587e8..6f86b330251 100644
--- a/mysql-test/r/ps.result
+++ b/mysql-test/r/ps.result
@@ -5163,3 +5163,14 @@ END;
 $$
 CALL p1('x');
 DROP PROCEDURE p1;
+create table t1 (b blob default '');
+prepare stmt from "alter table t1 force";
+execute stmt;
+execute stmt;
+execute stmt;
+set names latin1;
+prepare stmt from "alter table t1 modify b text character set utf8 default 'a'";
+execute stmt;
+execute stmt;
+execute stmt;
+drop table t1;
diff --git a/mysql-test/t/ps.test b/mysql-test/t/ps.test
index 565f831efdd..e051cdce179 100644
--- a/mysql-test/t/ps.test
+++ b/mysql-test/t/ps.test
@@ -4635,3 +4635,18 @@ DELIMITER ;$$
 --disable_result_log
 CALL p1('x');
 DROP PROCEDURE p1;
+
+#
+# MDEV-15746 ASAN heap-use-after-free in Item_change_list::rollback_item_tree_changes on ALTER executed as PS
+#
+create table t1 (b blob default '');
+prepare stmt from "alter table t1 force";
+execute stmt;
+execute stmt;
+execute stmt;
+set names latin1;
+prepare stmt from "alter table t1 modify b text character set utf8 default 'a'";
+execute stmt;
+execute stmt;
+execute stmt;
+drop table t1;
diff --git a/sql/sql_table.cc b/sql/sql_table.cc
index 9e7973b745c..1ed2194b09a 100644
--- a/sql/sql_table.cc
+++ b/sql/sql_table.cc
@@ -3378,6 +3378,8 @@ mysql_prepare_create_table(THD *thd, HA_CREATE_INFO *create_info,
     */
     if (sql_field->default_value &&
         sql_field->default_value->expr->basic_const_item() &&
+        (!sql_field->field ||
+         sql_field->field->default_value != sql_field->default_value) &&
         save_cs != sql_field->default_value->expr->collation.collation &&
         (sql_field->sql_type == MYSQL_TYPE_VAR_STRING ||
          sql_field->sql_type == MYSQL_TYPE_STRING ||