diff --git a/components/mobile/profile/ThemeSessionBridge.tsx b/components/mobile/profile/ThemeSessionBridge.tsx
index 5e5b3c4..7d00531 100644
--- a/components/mobile/profile/ThemeSessionBridge.tsx
+++ b/components/mobile/profile/ThemeSessionBridge.tsx
@@ -10,7 +10,7 @@
  * Renders nothing.
  */
 
-import { useEffect } from 'react';
+import { useEffect, useRef } from 'react';
 import { useTheme } from 'next-themes';
 import { useSession } from '@/lib/auth-client';
 
@@ -19,8 +19,15 @@ type SessionUserWithTheme = { theme?: 'light' | 'dark' | 'system' | string };
 export function ThemeSessionBridge() {
   const { data: session } = useSession();
   const { theme, setTheme } = useTheme();
+  // Sync server → client EXACTLY ONCE per tab session. better-auth's
+  // useSession (nanostores) can re-emit on focus / store refresh, which would
+  // otherwise call setTheme with the stale cached session.user.theme and
+  // revert the user's just-made selection. The PUT to /api/me/theme does NOT
+  // refresh the cached session, so any post-selection re-fire would clobber.
+  const hasSynced = useRef(false);
 
   useEffect(() => {
+    if (hasSynced.current) return;
     if (!session?.user) return;
     const serverTheme = (session.user as SessionUserWithTheme).theme;
     // Only enforce explicit choices. 'system' is the column default and may
@@ -32,12 +39,7 @@ export function ThemeSessionBridge() {
         setTheme(serverTheme);
       }
     }
-    // Deps intentionally exclude `theme`. This bridge syncs server → client
-    // on session establishment only. Including `theme` made the effect re-fire
-    // on every user selection and revert to the stale cached
-    // `session.user.theme` (the PUT to /api/me/theme does not refresh the
-    // better-auth session, so user.theme remains the pre-change value and
-    // "wins" against the new client value).
+    hasSynced.current = true;
     // eslint-disable-next-line react-hooks/exhaustive-deps
   }, [session?.user?.id, setTheme]);