diff --git a/src/db/sqlite/threads.ts b/src/db/sqlite/threads.ts
index 7200f2d..504cc73 100644
--- a/src/db/sqlite/threads.ts
+++ b/src/db/sqlite/threads.ts
@@ -117,6 +117,15 @@ export async function countThreadParticipants(threadId: string, rootMessageId: s
   return Number(row?.c ?? 0);
 }
 
+/** Everyone who wrote in a thread, the root's author included. */
+export async function listThreadParticipants(threadId: string, rootMessageId: string): Promise<string[]> {
+  const db = getSqliteDb();
+  const rows = db
+    .prepare(`SELECT DISTINCT sender_server_id AS id FROM messages WHERE thread_id = ? OR message_id = ?`)
+    .all(threadId, rootMessageId) as { id: string }[];
+  return rows.map((r) => r.id);
+}
+
 /** Up to three people who replied most recently in each thread, newest first. The root author isn't counted. */
 export async function listRecentRepliers(threadIds: string[]): Promise<Map<string, string[]>> {
   const out = new Map<string, string[]>();
diff --git a/src/socket/handlers/chat.ts b/src/socket/handlers/chat.ts
index fea6bc4..5e1cdd5 100644
--- a/src/socket/handlers/chat.ts
+++ b/src/socket/handlers/chat.ts
@@ -50,6 +50,7 @@ import {
   listThreadsByConversation,
   listThreadsByRootMessageIds,
   countThreadParticipants,
+  listThreadParticipants,
   listRecentRepliers,
   setThreadStatus,
   setThreadTags,
@@ -506,6 +507,7 @@ export function registerChatHandlers(ctx: HandlerContext): EventHandlerMap {
         // Same channel and permissions as any other message, plus a thread_id
         // so the client can place it. Threads live in channels, not DMs.
         let threadId: string | null = null;
+        let threadRoot: string | null = null;
         if (typeof payload.threadId === "string" && payload.threadId) {
           if (access.kind === "dm") {
             refuse({ error: "threads_not_allowed", message: "Threads are not available in direct messages." });
@@ -521,6 +523,7 @@ export function registerChatHandlers(ctx: HandlerContext): EventHandlerMap {
             return;
           }
           threadId = thread.thread_id;
+          threadRoot = thread.root_message_id;
         }
 
         // Identity verification
@@ -952,6 +955,24 @@ export function registerChatHandlers(ctx: HandlerContext): EventHandlerMap {
           }
         }
 
+        /* Everyone who wrote in the thread hears about a reply, and nobody else (GRYT-2008).
+           After the mention push, so a mention in a thread is still one notification. */
+        if (threadId && threadRoot && access.kind !== "dm") {
+          try {
+            const sender = auth.tokenPayload.serverUserId;
+            const blockers = await blockersOfSender(sender);
+            const told: string[] = [];
+            for (const id of await listThreadParticipants(threadId, threadRoot)) {
+              if (id === sender || blockers.has(id) || id === "system") continue;
+              if (!(await mayViewChannel(created.conversation_id, id))) continue;
+              told.push(id);
+            }
+            pushNotify(clientsInfo, told, "message", created.conversation_id, { preview: pushPreview });
+          } catch (err) {
+            consola.warn("thread push failed", created.message_id, err);
+          }
+        }
+
         // After the message is out, so a promotion can neither slow one down
         // nor stop one. One roles read on a server using none of this.
         const promoted = await applyAutoRoles(
diff --git a/src/socket/handlers/pushAudience.test.ts b/src/socket/handlers/pushAudience.test.ts
index f469873..a5078b6 100644
--- a/src/socket/handlers/pushAudience.test.ts
+++ b/src/socket/handlers/pushAudience.test.ts
@@ -516,3 +516,41 @@ describe("push:register", () => {
     assert.deepEqual(reply, { ok: false, error: "invalid_payload" });
   });
 });
+
+describe("thread replies (GRYT-2008)", () => {
+  async function thread(): Promise<string> {
+    const root = line("voice cuts out for me");
+    await send(alice, OPEN, root);
+    const posted = alice.emitted.find((e) => e.event === "chat:new" && (e.payload as { text?: string }).text === root)
+      ?.payload as { message_id: string };
+    await alice.handlers["thread:create"]({ accessToken: alice.accessToken, conversationId: OPEN, rootMessageId: posted.message_id });
+    const created = alice.emitted.find((e) => e.event === "thread:created")?.payload as { thread_id: string };
+    assert.ok(created?.thread_id, "no thread was created");
+    return created.thread_id;
+  }
+
+  async function reply(from: Member, threadId: string, text: string): Promise<void> {
+    await from.handlers["chat:send"]({ accessToken: from.accessToken, conversationId: OPEN, text, threadId });
+    const refused = from.emitted.find((e) => e.event === "chat:error" || e.event === "thread:error");
+    assert.equal(refused, undefined, `${from.name}'s reply was refused: ${JSON.stringify(refused?.payload)}`);
+  }
+
+  it("wake whoever started the thread or replied in it, and nobody else", async () => {
+    const id = await thread();
+    await reply(carol, id, line("same here"));
+    hits.length = 0;
+    resetPushState();
+    for (const m of [alice, carol, dave, erin]) away(m);
+    await reply(erin, id, line("try another headset"));
+    assert.deepEqual(await woken(), ["Alice:message", "Carol:message"]);
+  });
+
+  it("don't wake the person who replied", async () => {
+    const id = await thread();
+    hits.length = 0;
+    resetPushState();
+    away(alice);
+    await reply(alice, id, line("never mind, fixed it"));
+    assert.deepEqual(await woken(), []);
+  });
+});