diff --git a/libraries/liblmdb/lmdb.h b/libraries/liblmdb/lmdb.h
index 7719e32..aaaa292 100644
--- a/libraries/liblmdb/lmdb.h
+++ b/libraries/liblmdb/lmdb.h
@@ -353,7 +353,9 @@ typedef enum MDB_cursor_op {
 #define MDB_CURSOR_FULL	(-30787)
 	/** Page has not enough space - internal error */
 #define MDB_PAGE_FULL	(-30786)
-#define MDB_LAST_ERRCODE	MDB_PAGE_FULL
+	/** Database contents grew beyond environment mapsize */
+#define MDB_MAP_RESIZED	(-30785)
+#define MDB_LAST_ERRCODE	MDB_MAP_RESIZED
 /** @} */
 
 /** @brief Statistics for a database in the environment */
@@ -675,7 +677,9 @@ int  mdb_env_set_maxdbs(MDB_env *env, MDB_dbi dbs);
 	 * errors are:
 	 * <ul>
 	 *	<li>#MDB_PANIC - a fatal error occurred earlier and the environment
-	 *		must be shut down.
+-	 *		must be shut down.
+	 *	<li>#MDB_MAP_RESIZED - another process wrote data beyond this MDB_env's
+	 *		mapsize and the environment must be shut down.
 	 *	<li>ENOMEM - out of memory, or a read-only transaction was requested and
 	 *		the reader lock table is full. See #mdb_env_set_maxreaders().
 	 * </ul>
diff --git a/libraries/liblmdb/mdb.c b/libraries/liblmdb/mdb.c
index 7bfdfc2..40b9bda 100644
--- a/libraries/liblmdb/mdb.c
+++ b/libraries/liblmdb/mdb.c
@@ -1054,7 +1054,8 @@ static char *const mdb_errstr[] = {
 	"MDB_TLS_FULL: Thread-local storage keys full - too many environments open",
 	"MDB_TXN_FULL: Transaction has too many dirty pages - transaction too big",
 	"MDB_CURSOR_FULL: Internal error - cursor stack limit reached",
-	"MDB_PAGE_FULL: Internal error - page has no more space"
+	"MDB_PAGE_FULL: Internal error - page has no more space",
+	"MDB_MAP_RESIZED: Database contents grew beyond environment mapsize",
 };
 
 char *
@@ -1818,6 +1819,11 @@ mdb_txn_renew0(MDB_txn *txn)
 	if (txn->mt_numdbs > 2)
 		memset(txn->mt_dbflags+2, DB_STALE, txn->mt_numdbs-2);
 
+	if (env->me_maxpg < txn->mt_next_pgno) {
+		mdb_txn_reset0(txn);
+		return MDB_MAP_RESIZED;
+	}
+
 	return MDB_SUCCESS;
 }