diff --git a/js/js.libraries/src/html5/files.kt b/js/js.libraries/src/html5/files.kt
index 373cdf6f3d6..c3f4309d8d5 100644
--- a/js/js.libraries/src/html5/files.kt
+++ b/js/js.libraries/src/html5/files.kt
@@ -25,11 +25,16 @@ public class File() : Blob() {
 }
 
 native
-public open class Blob() {
-    public val size : Int = noImpl
-    public val type : String = noImpl
+public open class Blob(blobParts: Array<Any>? = undefined, options: BlobPropertyBag? = undefined) {
+    public val size: Int = noImpl
+    public val type: String = noImpl
     //Blob slice(optional long long start,
     //optional long long end,
     //optional DOMString contentType);
     //
 }
+
+native
+public trait BlobPropertyBag {
+    public val type: String
+}
\ No newline at end of file