diff --git a/src/main/browser-action-service.ts b/src/main/browser-action-service.ts
index ebab0dee..c37f9c0d 100644
--- a/src/main/browser-action-service.ts
+++ b/src/main/browser-action-service.ts
@@ -130,8 +130,8 @@ export function createBrowserActionService({
     return requireBrowserManager().launchLoginBrowser(socialAccountId, platform, loginUrl);
   }
 
-  function resetBrowserManager() {
-    browserManagerRef.current?.shutdown();
+  async function resetBrowserManager() {
+    await browserManagerRef.current?.shutdown();
     browserManagerRef.current = new BrowserManager(join(db.artifactsDir, "browser"));
   }
 
diff --git a/src/main/browser-manager.ts b/src/main/browser-manager.ts
index c9b5d987..2f25f4a9 100644
--- a/src/main/browser-manager.ts
+++ b/src/main/browser-manager.ts
@@ -300,10 +300,22 @@ export class BrowserManager {
     }
   }
 
-  shutdown() {
+  async shutdown() {
+    // Wait for each pending window-close to finish so any callers that chain
+    // `await shutdown()` before recreating the manager don't observe torn
+    // state (half-closed login windows still holding a partition).
+    const closePromises: Promise<void>[] = [];
     for (const [, win] of this.loginWindows) {
-      if (!win.isDestroyed()) win.close();
+      if (!win.isDestroyed()) {
+        closePromises.push(
+          new Promise<void>((resolve) => {
+            win.once("closed", () => resolve());
+            win.close();
+          }),
+        );
+      }
     }
+    await Promise.all(closePromises);
     this.loginWindows.clear();
     this.activeActionWindows.clear();
     this.cancelledActionIds.clear();
diff --git a/src/main/main-runtime-support.ts b/src/main/main-runtime-support.ts
index 4bb9ace5..b87bddb0 100644
--- a/src/main/main-runtime-support.ts
+++ b/src/main/main-runtime-support.ts
@@ -151,7 +151,7 @@ export function createMainRuntimeSupport(state: MainRuntimeState) {
       getWorkerProcess: () => requireServiceGraph().getWorkerService()?.getWorker() ?? null,
       resetAfterRestore: () => {
         initializeAgentTokenSigningKey(requireDb().profileDir);
-        requireBrowserActionService().resetBrowserManager();
+        void requireBrowserActionService().resetBrowserManager();
       },
       getApiPort: () => state.apiServer?.port ?? 0,
       notify: (options) => requireIpcSupport().notify(options),