diff --git a/mysql-test/suite/tokudb.bugs/r/alter_external_lock_assert.result b/mysql-test/suite/tokudb.bugs/r/alter_external_lock_assert.result
new file mode 100644
index 00000000000..7c06d4354cd
--- /dev/null
+++ b/mysql-test/suite/tokudb.bugs/r/alter_external_lock_assert.result
@@ -0,0 +1,21 @@
+set default_storage_engine=tokudb;
+DROP TABLE IF EXISTS p,i,t1_tokudb_tokudb_smallvc_250;
+BEGIN;
+CREATE TABLE t1_tokudb_tokudb_smallvc_250(
+c1 BLOB,
+c2 DATE,
+unique(c2)) ENGINE=tokudb ROW_FORMAT=tokudb_small;
+CREATE TEMPORARY TABLE p LIKE t1_tokudb_tokudb_smallvc_250;
+ALTER TABLE p RENAME t1_tokudb_tokudb_smallvc_250;
+CREATE TEMPORARY TABLE i SELECT 1 t1_tokudb_tokudb_smallvc_250;
+show tables;
+Tables_in_test
+t1_tokudb_tokudb_smallvc_250
+LOCK TABLE i READ;
+ALTER TABLE t1_tokudb_tokudb_smallvc_250 MODIFY c1 DATE;
+ALTER TABLE t1_tokudb_tokudb_smallvc_250 MODIFY c1 DATE;
+ALTER TABLE t1_tokudb_tokudb_smallvc_250 MODIFY c1 DATE;
+UNLOCK TABLES;
+COMMIT;
+DROP TABLE IF EXISTS i,p,t1_tokudb_tokudb_smallvc_250;
+DROP TABLE t1_tokudb_tokudb_smallvc_250;
diff --git a/mysql-test/suite/tokudb.bugs/t/alter_external_lock_assert.test b/mysql-test/suite/tokudb.bugs/t/alter_external_lock_assert.test
new file mode 100644
index 00000000000..176d2c8ded4
--- /dev/null
+++ b/mysql-test/suite/tokudb.bugs/t/alter_external_lock_assert.test
@@ -0,0 +1,26 @@
+# test case for Tokutek/mysql56#54, assert in tokudb::external_lock
+
+source include/have_tokudb.inc;
+set default_storage_engine=tokudb;
+disable_warnings;
+DROP TABLE IF EXISTS p,i,t1_tokudb_tokudb_smallvc_250;
+enable_warnings;
+BEGIN;
+CREATE TABLE t1_tokudb_tokudb_smallvc_250(
+c1 BLOB,
+c2 DATE,
+unique(c2)) ENGINE=tokudb ROW_FORMAT=tokudb_small;
+CREATE TEMPORARY TABLE p LIKE t1_tokudb_tokudb_smallvc_250;
+ALTER TABLE p RENAME t1_tokudb_tokudb_smallvc_250;
+CREATE TEMPORARY TABLE i SELECT 1 t1_tokudb_tokudb_smallvc_250;
+show tables;
+LOCK TABLE i READ;
+ALTER TABLE t1_tokudb_tokudb_smallvc_250 MODIFY c1 DATE;
+ALTER TABLE t1_tokudb_tokudb_smallvc_250 MODIFY c1 DATE;
+ALTER TABLE t1_tokudb_tokudb_smallvc_250 MODIFY c1 DATE;
+UNLOCK TABLES;
+COMMIT;
+disable_warnings;
+DROP TABLE IF EXISTS i,p,t1_tokudb_tokudb_smallvc_250;
+enable_warnings;
+DROP TABLE t1_tokudb_tokudb_smallvc_250;