diff --git a/src/box/txn.h b/src/box/txn.h
index 19330b1f02e0690ed47492282f1afecc5195f6f3..21858a6e2839143e501d971620b85e1cc7254f14 100644
--- a/src/box/txn.h
+++ b/src/box/txn.h
@@ -127,7 +127,7 @@ struct txn {
 	 * First statement at each statement-level.
 	 * Needed to rollback sub statements.
 	 */
-	struct stailq_entry *sub_stmt_begin[TXN_SUB_STMT_MAX];
+	struct stailq_entry *sub_stmt_begin[TXN_SUB_STMT_MAX + 1];
 	/** LSN of this transaction when written to WAL. */
 	int64_t signature;
 	/** Engine involved in multi-statement transaction. */