1 files changed, 1 insertions, 1 deletions

diff --git a/server/middlewares/cache/shared/api-cache.ts b/server/middlewares/cache/shared/api-cache.ts
index 9e15bf2d6..7c366db00 100644
--- a/server/middlewares/cache/shared/api-cache.ts
+++ b/server/middlewares/cache/shared/api-cache.ts
@@ -27,7 +27,7 @@ export class ApiCache {
   private readonly options: APICacheOptions
   private readonly timers: { [ id: string ]: NodeJS.Timeout } = {}
 
-  private index: { all: string[] } = { all: [] }
+  private readonly index: { all: string[] } = { all: [] }
 
   constructor (options: APICacheOptions) {
     this.options = {