diff --git a/web/src/blueslip.ts b/web/src/blueslip.ts
index 71b2d3f8bd..b39586b47c 100644
--- a/web/src/blueslip.ts
+++ b/web/src/blueslip.ts
@@ -88,7 +88,7 @@ export function warn(msg: string, more_info?: unknown): void {
 
 class BlueslipError extends Error {
     override name = "BlueslipError";
-    more_info?: unknown;
+    more_info?: object;
     constructor(msg: string, more_info?: object | undefined) {
         super(msg);
         if (more_info !== undefined) {