diff --git a/libraries/liblmdb/lmdb.h b/libraries/liblmdb/lmdb.h
index 61318ff..d5c70da 100644
--- a/libraries/liblmdb/lmdb.h
+++ b/libraries/liblmdb/lmdb.h
@@ -932,6 +932,8 @@ int mdb_env_set_assert(MDB_env *env, MDB_assert_func *func);
* This transaction will not perform any write operations.
*
#MDB_NOSYNC
* Don't flush system buffers to disk when committing this transaction.
+ * #MDB_NOMETASYNC
+ * Flush system buffers but omit metadata flush when committing this transaction.
*
* @param[out] txn Address where the new #MDB_txn handle will be stored
* @return A non-zero error value on failure and 0 on success. Some possible
diff --git a/libraries/liblmdb/mdb.c b/libraries/liblmdb/mdb.c
index 984a5bd..ffe0ad4 100644
--- a/libraries/liblmdb/mdb.c
+++ b/libraries/liblmdb/mdb.c
@@ -1085,6 +1085,7 @@ struct MDB_txn {
#define MDB_TXN_DIRTY 0x04 /**< must write, even if dirty list is empty */
#define MDB_TXN_SPILLS 0x08 /**< txn or a parent has spilled pages */
#define MDB_TXN_NOSYNC 0x10 /**< don't sync this txn on commit */
+#define MDB_TXN_NOMETASYNC 0x20 /**< don't sync meta for this txn on commit */
/** @} */
unsigned int mt_flags; /**< @ref mdb_txn */
/** #dirty_list room: Array size - \#dirty pages visible to this txn.
@@ -2758,6 +2759,8 @@ mdb_txn_begin(MDB_env *env, MDB_txn *parent, unsigned int flags, MDB_txn **ret)
} else {
if (flags & MDB_NOSYNC)
txn->mt_flags |= MDB_TXN_NOSYNC;
+ if (flags & MDB_NOMETASYNC)
+ txn->mt_flags |= MDB_TXN_NOMETASYNC;
txn->mt_cursors = (MDB_cursor **)(txn->mt_dbs + env->me_maxdbs);
if (parent) {
txn->mt_dbiseqs = parent->mt_dbiseqs;
@@ -3688,7 +3691,7 @@ mdb_env_write_meta(MDB_txn *txn)
__sync_synchronize();
#endif
mp->mm_txnid = txn->mt_txnid;
- if (F_ISSET(txn->mt_flags, MDB_TXN_NOSYNC))
+ if (txn->mt_flags & (MDB_TXN_NOSYNC|MDB_TXN_NOMETASYNC))
goto done;
if (!(env->me_flags & (MDB_NOMETASYNC|MDB_NOSYNC))) {
unsigned meta_size = env->me_psize;
@@ -3727,7 +3730,7 @@ mdb_env_write_meta(MDB_txn *txn)
/* Write to the SYNC fd */
mfd = ((env->me_flags & (MDB_NOSYNC|MDB_NOMETASYNC)) ||
- (txn->mt_flags & MDB_TXN_NOSYNC)) ?
+ (txn->mt_flags & (MDB_TXN_NOSYNC|MDB_TXN_NOMETASYNC))) ?
env->me_fd : env->me_mfd;
#ifdef _WIN32
{