diff --git a/frontend/src/routes/settings/Settings.tsx b/frontend/src/routes/settings/Settings.tsx
index 6957bb3..8fa3cc0 100644
--- a/frontend/src/routes/settings/Settings.tsx
+++ b/frontend/src/routes/settings/Settings.tsx
@@ -389,6 +389,7 @@ function AccountEditor({
   onSaved: () => void;
 }) {
   const t = useT();
+  const queryClient = useQueryClient();
   const detail = useQuery({ queryKey: ["account", accountId], queryFn: () => api.accountDetail(accountId) });
   const [displayName, setDisplayName] = useState("");
   const [color, setColor] = useState("#888888");
@@ -428,7 +429,10 @@ function AccountEditor({
       }
       return api.updateAccount(accountId, patch);
     },
-    onSuccess: onSaved,
+    onSuccess: (updated) => {
+      queryClient.setQueryData(["account", accountId], updated);
+      onSaved();
+    },
     onError: (e) => setError(e instanceof ApiError ? e.message : "Save failed"),
   });
 
@@ -519,6 +523,7 @@ function SignatureEditor({
   onSaved: () => void;
 }) {
   const t = useT();
+  const queryClient = useQueryClient();
   const detail = useQuery({
     queryKey: ["account", accountId],
     queryFn: () => api.accountDetail(accountId),
@@ -532,7 +537,12 @@ function SignatureEditor({
 
   const save = useMutation({
     mutationFn: () => api.updateAccount(accountId, { signature }),
-    onSuccess: onSaved,
+    // Keep the cached detail current: the editor seeds from it only once on mount,
+    // so a stale entry would reopen the editor with the old (e.g. empty) signature.
+    onSuccess: (updated) => {
+      queryClient.setQueryData(["account", accountId], updated);
+      onSaved();
+    },
     onError: (e) => setError(e instanceof ApiError ? e.message : "Save failed"),
   });