diff --git a/src/index.d.ts b/src/index.d.ts
index 5d0b749..8454042 100644
--- a/src/index.d.ts
+++ b/src/index.d.ts
@@ -1,5 +1,5 @@
 export const FS: {
-    writeFile: (fileName: string, binaryData: Uint8Array) => void,
+    writeFile: (fileName: string, binaryData: Uint8Array | string) => void,
     readFile: (fileName: string) => Uint8Array,
     unlink: (fileName: string) => void,
 }