diff --git a/src/index.d.ts b/src/index.d.ts
index 78b68cf..0827f2c 100644
--- a/src/index.d.ts
+++ b/src/index.d.ts
@@ -19,8 +19,8 @@ declare namespace Tesseract {
     readText(path: string, jobId?: string): Promise<ConfigResult>
     removeText(path: string, jobId?: string): Promise<ConfigResult>
     FS(method: string, args: any[], jobId?: string): Promise<ConfigResult>
-    loadLanguage(langs?: string, jobId?: string): Promise<ConfigResult>
-    initialize(langs?: string, oem?: OEM, jobId?: string): Promise<ConfigResult>
+    loadLanguage(langs?: string | Lang[], jobId?: string): Promise<ConfigResult>
+    initialize(langs?: string | Lang[], oem?: OEM, jobId?: string): Promise<ConfigResult>
     setParameters(params: Partial<WorkerParams>, jobId?: string): Promise<ConfigResult>
     recognize(image: ImageLike, options?: Partial<RecognizeOptions>, jobId?: string): Promise<RecognizeResult>
     detect(image: ImageLike, jobId?: string): Promise<DetectResult>
@@ -28,6 +28,11 @@ declare namespace Tesseract {
     getPDF(title?: string, textonly?: boolean, jobId?: string):Promise<GetPDFResult>
   }
 
+  interface Lang {
+    code: string;
+    data: unknown;
+  }
+
   interface WorkerOptions {
     corePath: string
     langPath: string