diff --git a/index.d.ts b/index.d.ts
index 44f9f35..2152db0 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -27,7 +27,7 @@ declare namespace arg {
 	}
 
 	export type Result<T extends Spec> = { _: string[] } & {
-		[K in keyof T]?: T[K] extends Handler
+		[K in keyof T as T[K] extends string ? never : K]?: T[K] extends Handler
 			? ReturnType<T[K]>
 			: T[K] extends [Handler]
 			? Array<ReturnType<T[K][0]>>