diff --git a/src/lib/consts.ts b/src/lib/consts.ts
index b12c901..4bae878 100644
--- a/src/lib/consts.ts
+++ b/src/lib/consts.ts
@@ -1,3 +1,4 @@
 export const REQUEST_ID_HEADER = 'x-request-id';
 export const REQUEST_ID_PARAM_NAME = 'requestId';
+export const USER_ID_PARAM_NAME = 'userId';
 export const TRACE_KEY = 'uber-trace-id';
diff --git a/src/types.ts b/src/types.ts
index ed516d1..44c2213 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -1,6 +1,6 @@
 import type {pino} from 'pino';
 
-import {REQUEST_ID_PARAM_NAME} from './lib/consts';
+import {REQUEST_ID_PARAM_NAME, USER_ID_PARAM_NAME} from './lib/consts';
 import type {LoggingLevel} from './lib/logging';
 
 export interface AppConfig {
@@ -46,6 +46,7 @@ export interface AppConfig {
 
 export interface AppContextParams {
     [REQUEST_ID_PARAM_NAME]?: string;
+    [USER_ID_PARAM_NAME]?: string;
 }
 
 export interface AppDynamicConfig {}