diff --git a/apps/web/src/components/chat/useComposerSend.ts b/apps/web/src/components/chat/useComposerSend.ts
index 1afe53a944707..79e1c35721c86 100644
--- a/apps/web/src/components/chat/useComposerSend.ts
+++ b/apps/web/src/components/chat/useComposerSend.ts
@@ -1171,9 +1171,12 @@ export function useComposerSend(input: ComposerSendInput) {
       : null;
     // Keep new-thread flows from reusing this draft while attachments and worktree setup settle.
     if (sentDraftThreadRef) markPromotedDraftThreadByRef(sentDraftThreadRef);
-    promptRef.current = "";
     clearComposerDraftContent(composerDraftTarget);
-    composerRef.current?.resetCursorState();
+    // The prompt ref and cursor belong to the thread on screen, which may no longer be this one.
+    if (currentRouteThreadKeyRef.current === routeThreadKey) {
+      promptRef.current = "";
+      composerRef.current?.resetCursorState();
+    }
 
     const title = deriveThreadTitleSeed({
       text: messageTextForSend,