diff --git a/recaptcha/recaptcha.d.ts b/recaptcha/recaptcha.d.ts
index 410db7651..db2096275 100644
--- a/recaptcha/recaptcha.d.ts
+++ b/recaptcha/recaptcha.d.ts
@@ -6,7 +6,7 @@
 declare class Recaptcha {
 	constructor();
 	static reload(): void;
-	static switch_type(newtype: any);
+	static switch_type(newtype: string): void;
 	static showhelp(): void;
 	static get_challenge(): string;
 	static get_response(): string;
@@ -36,4 +36,4 @@ interface CustomTranslations {
 	incorrect_try_again?: string;
 	image_alt_text?: string;
 	privacy_and_terms?: string;
-}
\ No newline at end of file
+}