diff --git a/sql/mdl.cc b/sql/mdl.cc
index 944d4cd4d4300..16bf85e0a61ca 100644
--- a/sql/mdl.cc
+++ b/sql/mdl.cc
@@ -114,6 +114,7 @@ PSI_stage_info MDL_key::m_namespace_to_wait_state_name[NAMESPACE_END]=
 
 static const LEX_STRING lock_types[]=
 {
+  {},
   { C_STRING_WITH_LEN("MDL_INTENTION_EXCLUSIVE") },
   { C_STRING_WITH_LEN("MDL_SHARED") },
   { C_STRING_WITH_LEN("MDL_SHARED_HIGH_PRIO") },
@@ -129,6 +130,7 @@ static const LEX_STRING lock_types[]=
 
 static const LEX_STRING backup_lock_types[]=
 {
+  {},
   { C_STRING_WITH_LEN("MDL_BACKUP_START") },
   { C_STRING_WITH_LEN("MDL_BACKUP_FLUSH") },
   { C_STRING_WITH_LEN("MDL_BACKUP_WAIT_FLUSH") },
@@ -2154,6 +2156,7 @@ void MDL_lock::reschedule_waiters()
 const MDL_lock::bitmap_t
 MDL_lock::MDL_scoped_lock::m_granted_incompatible[MDL_TYPE_END]=
 {
+  0,
   MDL_BIT(MDL_EXCLUSIVE) | MDL_BIT(MDL_SHARED),
   MDL_BIT(MDL_EXCLUSIVE) | MDL_BIT(MDL_INTENTION_EXCLUSIVE),
   0, 0, 0, 0, 0, 0, 0,
@@ -2163,6 +2166,7 @@ MDL_lock::MDL_scoped_lock::m_granted_incompatible[MDL_TYPE_END]=
 const MDL_lock::bitmap_t
 MDL_lock::MDL_scoped_lock::m_waiting_incompatible[MDL_TYPE_END]=
 {
+  0,
   MDL_BIT(MDL_EXCLUSIVE) | MDL_BIT(MDL_SHARED),
   MDL_BIT(MDL_EXCLUSIVE), 0, 0, 0, 0, 0, 0, 0, 0
 };
@@ -2227,6 +2231,7 @@ MDL_lock::MDL_scoped_lock::m_waiting_incompatible[MDL_TYPE_END]=
 const MDL_lock::bitmap_t
 MDL_lock::MDL_object_lock::m_granted_incompatible[MDL_TYPE_END]=
 {
+  0,
   0,
   MDL_BIT(MDL_EXCLUSIVE),
   MDL_BIT(MDL_EXCLUSIVE),
@@ -2255,6 +2260,7 @@ MDL_lock::MDL_object_lock::m_granted_incompatible[MDL_TYPE_END]=
 const MDL_lock::bitmap_t
 MDL_lock::MDL_object_lock::m_waiting_incompatible[MDL_TYPE_END]=
 {
+  0,
   0,
   MDL_BIT(MDL_EXCLUSIVE),
   0,
@@ -2330,6 +2336,7 @@ MDL_lock::MDL_object_lock::m_waiting_incompatible[MDL_TYPE_END]=
 const MDL_lock::bitmap_t
 MDL_lock::MDL_backup_lock::m_granted_incompatible[MDL_BACKUP_END]=
 {
+  0,
   /* MDL_BACKUP_START */
   MDL_BIT(MDL_BACKUP_START) | MDL_BIT(MDL_BACKUP_FLUSH) | MDL_BIT(MDL_BACKUP_WAIT_FLUSH) | MDL_BIT(MDL_BACKUP_WAIT_DDL) | MDL_BIT(MDL_BACKUP_WAIT_COMMIT) | MDL_BIT(MDL_BACKUP_BLOCK_DDL),
   MDL_BIT(MDL_BACKUP_START),
@@ -2357,6 +2364,7 @@ MDL_lock::MDL_backup_lock::m_granted_incompatible[MDL_BACKUP_END]=
 const MDL_lock::bitmap_t
 MDL_lock::MDL_backup_lock::m_waiting_incompatible[MDL_BACKUP_END]=
 {
+  0,
   /* MDL_BACKUP_START */
   MDL_BIT(MDL_BACKUP_FLUSH) | MDL_BIT(MDL_BACKUP_WAIT_FLUSH) | MDL_BIT(MDL_BACKUP_WAIT_DDL) | MDL_BIT(MDL_BACKUP_WAIT_COMMIT) | MDL_BIT(MDL_BACKUP_BLOCK_DDL),
   0,
diff --git a/sql/mdl.h b/sql/mdl.h
index 1b01bcf3ecb7b..adafcfe44c8e7 100644
--- a/sql/mdl.h
+++ b/sql/mdl.h
@@ -138,7 +138,7 @@ enum enum_mdl_type {
     that not-inited request has MDL_INTENTION_EXCLUSIVE.
     Must fix tests, as at least mysql_rm_table_no_locks() depends on this.
   */
-  MDL_NOT_INITIALIZED= -1,
+  MDL_NOT_INITIALIZED= 0,
   /*
     An intention exclusive metadata lock (IX). Used only for scoped locks.
     Owner of this type of lock can acquire upgradable exclusive locks on
@@ -149,7 +149,7 @@ enum enum_mdl_type {
     object metadata. Object may refer table, stored procedure, trigger,
     view/etc.
   */
-  MDL_INTENTION_EXCLUSIVE= 0,
+  MDL_INTENTION_EXCLUSIVE,
   /*
     A shared metadata lock (S).
     To be used in cases when we are interested in object metadata only
@@ -273,51 +273,51 @@ enum enum_mdl_type {
 /**
   Block concurrent backup
 */
-#define MDL_BACKUP_START enum_mdl_type(0)
+#define MDL_BACKUP_START enum_mdl_type(1)
 /**
    Block new write requests to non transactional tables
 */
-#define MDL_BACKUP_FLUSH enum_mdl_type(1)
+#define MDL_BACKUP_FLUSH enum_mdl_type(2)
 /**
    In addition to previous locks, blocks running requests to non trans tables
    Used to wait until all DML usage of on trans tables are finished
 */
-#define MDL_BACKUP_WAIT_FLUSH enum_mdl_type(2)
+#define MDL_BACKUP_WAIT_FLUSH enum_mdl_type(3)
 /**
    In addition to previous locks, blocks new DDL's from starting
 */
-#define MDL_BACKUP_WAIT_DDL enum_mdl_type(3)
+#define MDL_BACKUP_WAIT_DDL enum_mdl_type(4)
 /**
    In addition to previous locks, blocks commits
 */
-#define MDL_BACKUP_WAIT_COMMIT enum_mdl_type(4)
+#define MDL_BACKUP_WAIT_COMMIT enum_mdl_type(5)
 
 /**
   Blocks (or is blocked by) statements that intend to modify data. Acquired
   before commit lock by FLUSH TABLES WITH READ LOCK.
 */
-#define MDL_BACKUP_FTWRL1 enum_mdl_type(5)
+#define MDL_BACKUP_FTWRL1 enum_mdl_type(6)
 
 /**
   Blocks (or is blocked by) commits. Acquired after global read lock by
   FLUSH TABLES WITH READ LOCK.
 */
-#define MDL_BACKUP_FTWRL2 enum_mdl_type(6)
+#define MDL_BACKUP_FTWRL2 enum_mdl_type(7)
 
-#define MDL_BACKUP_DML enum_mdl_type(7)
-#define MDL_BACKUP_TRANS_DML enum_mdl_type(8)
-#define MDL_BACKUP_SYS_DML enum_mdl_type(9)
+#define MDL_BACKUP_DML enum_mdl_type(8)
+#define MDL_BACKUP_TRANS_DML enum_mdl_type(9)
+#define MDL_BACKUP_SYS_DML enum_mdl_type(10)
 
 /**
   Must be acquired by DDL statements that intend to modify data.
   Currently it's also used for LOCK TABLES.
 */
-#define MDL_BACKUP_DDL enum_mdl_type(10)
+#define MDL_BACKUP_DDL enum_mdl_type(11)
 
 /**
    Blocks new DDL's. Used by backup code to enable DDL logging
 */
-#define MDL_BACKUP_BLOCK_DDL enum_mdl_type(11)
+#define MDL_BACKUP_BLOCK_DDL enum_mdl_type(12)
 
 /*
   Statement is modifying data, but will not block MDL_BACKUP_DDL or earlier
@@ -326,13 +326,13 @@ enum enum_mdl_type {
   MDL_BACKUP_ALTER_COPY while alter table is copying or modifying data.
 */
 
-#define MDL_BACKUP_ALTER_COPY enum_mdl_type(12)
+#define MDL_BACKUP_ALTER_COPY enum_mdl_type(13)
 
 /**
   Must be acquired during commit.
 */
-#define MDL_BACKUP_COMMIT enum_mdl_type(13)
-#define MDL_BACKUP_END enum_mdl_type(14)
+#define MDL_BACKUP_COMMIT enum_mdl_type(14)
+#define MDL_BACKUP_END enum_mdl_type(15)
 
 
 /** Duration of metadata lock. */