diff --git a/lib/db/queries.ts b/lib/db/queries.ts
index d37ea9621..067a7f7e1 100644
--- a/lib/db/queries.ts
+++ b/lib/db/queries.ts
@@ -3668,6 +3668,15 @@ export async function getAllSystemSettings() {
   }
 }
 
+function normalizeSystemSettingUpdatedBy(updatedBy: string | null | undefined) {
+  const normalized = String(updatedBy || "").trim();
+  return /^[0-9a-f]{8}-[0-9a-f]{4}-[1-5][0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$/i.test(
+    normalized
+  )
+    ? normalized
+    : null;
+}
+
 export async function upsertSystemSetting({
   key,
   value,
@@ -3675,22 +3684,24 @@ export async function upsertSystemSetting({
 }: {
   key: string;
   value: any;
-  updatedBy: string;
+  updatedBy: string | null | undefined;
 }) {
+  const normalizedUpdatedBy = normalizeSystemSettingUpdatedBy(updatedBy);
+
   try {
     return await db
       .insert(systemSettings)
       .values({
         key,
         value,
-        updatedBy,
+        updatedBy: normalizedUpdatedBy,
         updatedAt: new Date(),
       })
       .onConflictDoUpdate({
         target: systemSettings.key,
         set: {
           value,
-          updatedBy,
+          updatedBy: normalizedUpdatedBy,
           updatedAt: new Date(),
         },
       })