diff --git a/types/superagent/index.d.ts b/types/superagent/index.d.ts
index 9c3706d574..e02747ac5d 100644
--- a/types/superagent/index.d.ts
+++ b/types/superagent/index.d.ts
@@ -94,7 +94,7 @@ declare namespace request {
     interface Request extends Promise<Response> /* extends NodeJS.WritableStream */ {
         abort(): void;
         accept(type: string): this;
-        attach(field: string, file: string, filename?: string): this;
+        attach(field: string, file: string | Blob, filename?: string): this;
         auth(user: string, name: string): this;
         buffer(val?: boolean): this;
         clearTimeout(): this;
diff --git a/types/superagent/superagent-tests.ts b/types/superagent/superagent-tests.ts
index 9d0e5f0ac9..9e8dc0aa96 100644
--- a/types/superagent/superagent-tests.ts
+++ b/types/superagent/superagent-tests.ts
@@ -262,11 +262,13 @@ stream.pipe(req);
 })();
 
 // Attaching files
+const blob: Blob = new File([], 'thor.png');
 request
     .post('/upload')
     .attach('avatar', 'path/to/tobi.png', 'user.png')
     .attach('image', 'path/to/loki.png')
     .attach('file', 'path/to/jane.png')
+    .attach('blob', blob)
     .end(callback);
 
 // Field values