diff --git a/src/utils.ts b/src/utils.ts
index 5bf2dd2..5118c78 100644
--- a/src/utils.ts
+++ b/src/utils.ts
@@ -17,8 +17,6 @@ settings.subscribe(b => {
 
 const generateThumbnail = async (f: File): Promise<Buffer> => {
     const can = document.createElement("canvas");
-    can.width = 125;
-    can.height = 125;
 
     const [sw, sh] = [125, 125];
     const url = URL.createObjectURL(f);
@@ -59,7 +57,7 @@ const generateThumbnail = async (f: File): Promise<Buffer> => {
 
     ctx.drawImage(source, 0, 0, dims[0], dims[1]);
 
-    const blob = await new Promise<Blob | null>(_ => can.toBlob(_, "image/jpg"));
+    const blob = await new Promise<Blob | null>(_ => can.toBlob(_));
     if (!blob)
         return Buffer.alloc(0);
     return Buffer.from(await blob.arrayBuffer());