diff --git a/packages/ui/certd-server/src/config/config.default.ts b/packages/ui/certd-server/src/config/config.default.ts
index e1c63b8e..cccbac7e 100644
--- a/packages/ui/certd-server/src/config/config.default.ts
+++ b/packages/ui/certd-server/src/config/config.default.ts
@@ -16,7 +16,7 @@ const development = {
   staticFile: {
     usePrecompiledGzip: true,
     buffer: true,
-    cacheControl: 'maxAge=' + 30 * 24 * 60 * 60 * 1000,
+    maxAge: 30 * 24 * 60 * 60 * 1000,
     gzip: true,
     dirs: {
       default: {