diff --git a/index.d.ts b/index.d.ts
index e91f89a..6bc85f0 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -479,6 +479,7 @@ declare global {
                 grayscale?: boolean
                 quality?: number
                 lossless?: boolean
+                outputType?: "jpg" | "jpeg" | "png" | "webp"
             }[]
         ): void
     }