diff --git a/types/blob-util/blob-util-tests.ts b/types/blob-util/blob-util-tests.ts
index af860a7ee1..d05b401116 100644
--- a/types/blob-util/blob-util-tests.ts
+++ b/types/blob-util/blob-util-tests.ts
@@ -13,5 +13,6 @@ blobUtil.blobToBase64String(testBlob); // $ExpectType Promise<string>
 blobUtil.blobToBinaryString(testBlob); // $ExpectType Promise<string>
 blobUtil.canvasToBlob(new HTMLCanvasElement()); // $ExpectType Promise<Blob>
 blobUtil.dataURLToBlob('data:abcd'); // $ExpectType Promise<Blob>
+blobUtil.blobToDataURL(testBlob); // $ExpectType Promise<string>
 blobUtil.imgSrcToDataURL('test.jpg'); // $ExpectType Promise<string>
 blobUtil.revokeObjectURL('blob:example'); // $ExpectType void
diff --git a/types/blob-util/index.d.ts b/types/blob-util/index.d.ts
index ce99c3d893..b8926722cf 100644
--- a/types/blob-util/index.d.ts
+++ b/types/blob-util/index.d.ts
@@ -12,6 +12,7 @@ export function binaryStringToBlob(binary: string, type?: string): Promise<Blob>
 export function blobToBase64String(blob: Blob): Promise<string>;
 export function base64StringToBlob(base64: string, type?: string): Promise<Blob>;
 export function dataURLToBlob(dataURL: string): Promise<Blob>;
+export function blobToDataURL(blob: Blob): Promise<string>;
 export function imgSrcToDataURL(src: string, type?: string, crossOrigin?: string): Promise<string>;
 export function canvasToBlob(canvas: HTMLCanvasElement, type?: string): Promise<Blob>;
 export function imgSrcToBlob(src: string, type?: string, crossOrigin?: string): Promise<Blob>;