diff --git a/src/assert.d.ts b/src/assert.d.ts
index c6f4099..dadf1dd 100644
--- a/src/assert.d.ts
+++ b/src/assert.d.ts
@@ -4,6 +4,8 @@ export type Message = string | Error;
 export function ok(actual: any, msg?: Message): asserts actual;
 export function is<Actual, Expects extends Actual>(actual: Actual, expected: Expects, msg?: Message): void;
 export function equal<Actual, Expects extends Actual>(actual: Actual, expected: Expects, msg?: Message): void;
+export function equal<Actual extends Expects, Expects>(actual: Actual, expected: Expects, msg?: Message): void;
+export function equal<Actual, Expects>(actual: Actual, expected: Expects, msg?: Message): void;
 export function type(actual: any, expects: Types, msg?: Message): void;
 export function instance(actual: any, expects: any, msg?: Message): void;
 export function snapshot(actual: string, expects: string, msg?: Message): void;