diff --git a/desktop/src/features/chats/lib/chatWorkAutomation.ts b/desktop/src/features/chats/lib/chatWorkAutomation.ts
index 25e3127a08..ee02f9b9f5 100644
--- a/desktop/src/features/chats/lib/chatWorkAutomation.ts
+++ b/desktop/src/features/chats/lib/chatWorkAutomation.ts
@@ -143,3 +143,33 @@ export function useChatWorkAutomation(chatId: string): ChatWorkAutomation {
 
   return state;
 }
+
+const PR_STORAGE_PREFIX = "buzz:chat-work-pr:v1";
+
+/**
+ * The PR pinned to a chat. Posted links age out of the windowed message
+ * fetch and branch discovery can resolve several chats sharing a reused
+ * worktree to the same PR — the pin keeps each chat on the PR it actually
+ * resolved first, with posted links always overriding.
+ */
+export function readChatPinnedPr(chatId: string): string | null {
+  if (typeof window === "undefined") {
+    return null;
+  }
+  try {
+    return window.localStorage.getItem(`${PR_STORAGE_PREFIX}:${chatId}`);
+  } catch {
+    return null;
+  }
+}
+
+export function writeChatPinnedPr(chatId: string, href: string) {
+  if (typeof window === "undefined") {
+    return;
+  }
+  try {
+    window.localStorage.setItem(`${PR_STORAGE_PREFIX}:${chatId}`, href);
+  } catch {
+    // Best-effort.
+  }
+}
diff --git a/desktop/src/features/chats/ui/ChatWorkPanel.tsx b/desktop/src/features/chats/ui/ChatWorkPanel.tsx
index 574f6f7bc7..4d14b03e50 100644
--- a/desktop/src/features/chats/ui/ChatWorkPanel.tsx
+++ b/desktop/src/features/chats/ui/ChatWorkPanel.tsx
@@ -11,8 +11,10 @@ import {
 } from "lucide-react";
 
 import {
+  readChatPinnedPr,
   updateChatWorkAutomation,
   useChatWorkAutomation,
+  writeChatPinnedPr,
 } from "@/features/chats/lib/chatWorkAutomation";
 import {
   type GithubCheckSummary,
@@ -83,11 +85,20 @@ export function ChatWorkPanel({
   // hidden panel stops polling entirely.
   const monitorActive =
     open || automation.autoFixCi || automation.addressComments;
+  // Pin resolution order: a link posted in THIS chat wins, then the chat's
+  // previously pinned PR, then branch discovery — discovery alone is
+  // ambiguous when agents reuse a worktree across chats in one project.
+  const pinnedHref = React.useMemo(() => readChatPinnedPr(chatId), [chatId]);
   const discoveredPrQuery = useGithubPrForBranchQuery(
-    monitorActive && !prHref ? projectPath : null,
+    monitorActive && !prHref && !pinnedHref ? projectPath : null,
     branch,
   );
-  const effectiveHref = prHref ?? discoveredPrQuery.data ?? null;
+  const effectiveHref = prHref ?? pinnedHref ?? discoveredPrQuery.data ?? null;
+  React.useEffect(() => {
+    if (effectiveHref && effectiveHref !== readChatPinnedPr(chatId)) {
+      writeChatPinnedPr(chatId, effectiveHref);
+    }
+  }, [chatId, effectiveHref]);
   const preview = effectiveHref
     ? parseSupportedLinkPreview(effectiveHref)
     : null;