diff --git a/packages/node/src/types/user.ts b/packages/node/src/types/user.ts
index 4b7d916..f08dea0 100644
--- a/packages/node/src/types/user.ts
+++ b/packages/node/src/types/user.ts
@@ -81,6 +81,11 @@ export type ExperimentUser = {
    */
   library?: string;
 
+  /**
+   * Predefined field, must be manually provided
+   */
+  ip_address?: string;
+
   /**
    * Custom user properties
    */