diff --git a/apps/server/src/utils/fileManagement.ts b/apps/server/src/utils/fileManagement.ts
index 8911c3c5e..6ec11e32a 100644
--- a/apps/server/src/utils/fileManagement.ts
+++ b/apps/server/src/utils/fileManagement.ts
@@ -19,7 +19,8 @@ export function ensureDirectory(directory: string): void {
 /**
  * Ensures that a filename ends with .json extension
  */
-export function ensureJsonExtension(filename: string): string {
+export function ensureJsonExtension(filename: string | undefined): string | undefined {
+  if (!filename) return filename;
   return filename.endsWith('.json') ? filename : `${filename}.json`;
 }