diff --git a/util/guards.ts b/util/guards.ts
index 5ae448c..6dd31b3 100644
--- a/util/guards.ts
+++ b/util/guards.ts
@@ -1 +1,2 @@
 export type NonEmptyArray<T> = [T, ...T[]];
+export type Constructor<T> = new(...args: Array<any>) => T;