diff --git a/packages/better-auth/src/plugins/device-authorization/index.ts b/packages/better-auth/src/plugins/device-authorization/index.ts
index e69b44cab9..6597e6b37a 100644
--- a/packages/better-auth/src/plugins/device-authorization/index.ts
+++ b/packages/better-auth/src/plugins/device-authorization/index.ts
@@ -835,6 +835,14 @@ Follow [rfc8628#section-3.4](https://datatracker.ietf.org/doc/html/rfc8628#secti
 							description: "The user code to deny",
 						}),
 					}),
+					error: z.object({
+						error: z.enum(["invalid_request", "expired_token"]).meta({
+							description: "Error code",
+						}),
+						error_description: z.string().meta({
+							description: "Detailed error description",
+						}),
+					}),
 					metadata: {
 						openapi: {
 							description: "Deny device authorization",