diff --git a/lib/ddl/tests/ddl_test.php b/lib/ddl/tests/ddl_test.php
index e317c5f8c4f..0338badb4a3 100644
--- a/lib/ddl/tests/ddl_test.php
+++ b/lib/ddl/tests/ddl_test.php
@@ -340,7 +340,7 @@ class core_ddl_testcase extends database_driver_testcase {
         // Weird column names - the largest allowed.
         $table = new xmldb_table('test_table3');
         $table->add_field('id', XMLDB_TYPE_INTEGER, '10', null, XMLDB_NOTNULL, XMLDB_SEQUENCE, null);
-        $table->add_field('abcdef____0123456789_______xyz', XMLDB_TYPE_INTEGER, '10', null, XMLDB_NOTNULL, null, '2');
+        $table->add_field(str_repeat('b', xmldb_field::NAME_MAX_LENGTH), XMLDB_TYPE_INTEGER, '10', null, XMLDB_NOTNULL, null, '2');
         $table->add_key('primary', XMLDB_KEY_PRIMARY, array('id'));
         $table->setComment("This is a test'n drop table. You can drop it safely");
 
@@ -350,10 +350,10 @@ class core_ddl_testcase extends database_driver_testcase {
         $this->assertTrue($dbman->table_exists($table));
         $dbman->drop_table($table);
 
-        // Too long field name - max 30.
+        // Too long field name.
         $table = new xmldb_table('test_table4');
         $table->add_field('id', XMLDB_TYPE_INTEGER, '10', null, XMLDB_NOTNULL, XMLDB_SEQUENCE, null);
-        $table->add_field('abcdeabcdeabcdeabcdeabcdeabcdez', XMLDB_TYPE_INTEGER, '10', null, XMLDB_NOTNULL, null, '2');
+        $table->add_field(str_repeat('a', xmldb_field::NAME_MAX_LENGTH + 1), XMLDB_TYPE_INTEGER, '10', null, XMLDB_NOTNULL, null, '2');
         $table->add_key('primary', XMLDB_KEY_PRIMARY, array('id'));
         $table->setComment("This is a test'n drop table. You can drop it safely");