diff --git a/types/koa-router/index.d.ts b/types/koa-router/index.d.ts
index ba7815ef54..b543a764b0 100644
--- a/types/koa-router/index.d.ts
+++ b/types/koa-router/index.d.ts
@@ -34,15 +34,25 @@ declare module Router {
 
     export interface IRouterOptions {
         /**
-         * Router prefixes
+         * Prefix for all routes.
          */
         prefix?: string;
         /**
-         * HTTP verbs
+         * Methods which should be supported by the router.
          */
         methods?: string[];
         routerPath?: string;
+        /**
+         * Whether or not routing should be case-sensitive.
+         */
         sensitive?: boolean;
+        /**
+         * Whether or not routes should matched strictly.
+         *
+         * If strict matching is enabled, the trailing slash is taken into
+         * account when matching routes.
+         */
+        strict?: boolean;
     }
 
     export interface IRouterContext extends Koa.Context {