diff --git a/types/jsqrcode/index.d.ts b/types/jsqrcode/index.d.ts
index fd3948c7b0..e7768d593f 100644
--- a/types/jsqrcode/index.d.ts
+++ b/types/jsqrcode/index.d.ts
@@ -480,7 +480,7 @@ declare const qrcode: {
 	readonly sizeOfDataLengthInfo: [[10, 9, 8, 8], [12, 11, 16, 10], [14, 13, 16, 12]],
 
 	// tslint:disable-next-line:prefer-method-signature
-	callback: () => void,
+	callback: (result: string) => void,
 
 	orderBestPatterns(patterns: AlignmentPattern[]): void,