diff --git a/.eslintrc b/.eslintrc
index 879d41e7..5bee3300 100644
--- a/.eslintrc
+++ b/.eslintrc
@@ -22,8 +22,7 @@
 			"rules": {
 				"@typescript-eslint/no-floating-promises": "off",
 				"no-duplicate-imports": "off",
-				"no-extra-parens": "off",
-				"@typescript-eslint/dot-notation": "off"
+				"no-extra-parens": "off"
 			}
 		},
 		{
diff --git a/src/lib/http/middleware/authenticate.ts b/src/lib/http/middleware/authenticate.ts
index 060adba5..da21f707 100644
--- a/src/lib/http/middleware/authenticate.ts
+++ b/src/lib/http/middleware/authenticate.ts
@@ -21,7 +21,7 @@ export const authenticate: ExtendedMiddleware = async (ctx, next) => {
 			return;
 		}
 
-		ctx.state['userId'] = userId;
+		ctx.state.userId = userId;
 	}
 
 	return next();
diff --git a/src/lib/rate-limiter.ts b/src/lib/rate-limiter.ts
index c47c407b..deabd8b5 100644
--- a/src/lib/rate-limiter.ts
+++ b/src/lib/rate-limiter.ts
@@ -30,9 +30,9 @@ export const rateLimit = async (ctx: ExtendedContext, numberOfProbes: number) =>
 	let rateLimiter: RateLimiterRedis;
 	let id: string;
 
-	if (ctx.state['userId']) {
+	if (ctx.state.userId) {
 		rateLimiter = authenticatedRateLimiter;
-		id = ctx.state['userId'] as string;
+		id = ctx.state.userId;
 	} else {
 		rateLimiter = anonymousRateLimiter;
 		id = requestIp.getClientIp(ctx.req) ?? '';
diff --git a/src/types.d.ts b/src/types.d.ts
index 0573b54b..0a804c86 100644
--- a/src/types.d.ts
+++ b/src/types.d.ts
@@ -2,7 +2,7 @@ import type Koa from 'koa';
 import type Router from '@koa/router';
 import type { DocsLinkContext } from './lib/http/middleware/docs-link.js';
 
-export type CustomState = Koa.DefaultState;
+export type CustomState = Koa.DefaultState & { userId?: string };
 export type CustomContext = Koa.DefaultContext & DocsLinkContext;
 
 export type ExtendedContext = Router.RouterContext<CustomState, CustomContext>;