diff --git a/index.d.ts b/index.d.ts
index 3ed7caa5f..ec4807540 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -552,7 +552,7 @@ declare module 'snowflake-sdk' {
 
     export interface StatementOption {
         sqlText: string;
-        complete: StatementCallback;
+        complete?: StatementCallback;
 
         /**
          * Enable asynchronous queries by including asyncExec: true in the connection.execute method.
@@ -863,4 +863,4 @@ declare module 'snowflake-sdk' {
      * Creates a connection pool for Snowflake connections.
      */
     export function createPool(options: ConnectionOptions, poolOptions?: PoolOptions): Pool<Connection>;
-}
\ No newline at end of file
+}