diff --git a/src/main/mirror-connection.ts b/src/main/mirror-connection.ts
index c026923..868b20a 100644
--- a/src/main/mirror-connection.ts
+++ b/src/main/mirror-connection.ts
@@ -8,6 +8,9 @@ import { encodeFrame, FrameReader, OP_FRAME, OP_HANDSHAKE } from './ipc-protocol
 export class MirrorConnection {
   private readonly sock: net.Socket
   private readonly reader = new FrameReader()
+  private ready = false
+  private pending: Buffer[] = []
+  private closeAfterPending = false
 
   constructor(socketPath: string, handshakePayload: Buffer, onClose: () => void) {
     this.sock = net.createConnection(socketPath)
@@ -16,25 +19,39 @@ export class MirrorConnection {
       this.sock.write(encodeFrame(OP_HANDSHAKE, handshakePayload))
     })
 
-    // Drain responses; the mirror connection only needs to look like a real client.
-    this.sock.on('data', (chunk) => this.reader.push(chunk))
+    // Discord sends a READY dispatch after the handshake; only once that
+    // arrives will it accept further commands like SET_ACTIVITY.
+    this.sock.on('data', (chunk) => {
+      const hadFrames = this.reader.push(chunk).length > 0
+      if (hadFrames && !this.ready) {
+        this.ready = true
+        for (const frame of this.pending.splice(0)) this.sock.write(frame)
+        if (this.closeAfterPending) this.sock.end()
+      }
+    })
 
     this.sock.on('error', onClose)
     this.sock.on('close', onClose)
   }
 
   sendActivity(payload: Buffer): void {
-    if (this.sock.writable) {
-      this.sock.write(encodeFrame(OP_FRAME, payload))
+    const frame = encodeFrame(OP_FRAME, payload)
+    if (this.ready) {
+      if (this.sock.writable) this.sock.write(frame)
+    } else {
+      this.pending.push(frame)
     }
   }
 
-  /** Sends a final frame and closes the connection once it has been flushed. */
+  /** Sends a final frame (after the handshake) and closes the connection once it has been flushed. */
   sendActivityAndClose(payload: Buffer): void {
-    if (this.sock.writable) {
-      this.sock.end(encodeFrame(OP_FRAME, payload))
+    const frame = encodeFrame(OP_FRAME, payload)
+    if (this.ready) {
+      if (this.sock.writable) this.sock.end(frame)
+      else this.sock.destroy()
     } else {
-      this.sock.destroy()
+      this.pending.push(frame)
+      this.closeAfterPending = true
     }
   }
 
diff --git a/src/main/relay.ts b/src/main/relay.ts
index 7182a01..6895bce 100644
--- a/src/main/relay.ts
+++ b/src/main/relay.ts
@@ -388,9 +388,14 @@ export class RpcRelay extends EventEmitter {
 
       let mirror = this.mirrors.get(index)
       if (!mirror) {
-        mirror = new MirrorConnection(mirrorPath, handshakePayload, () =>
-          this.mirrors.delete(index)
+        const newMirror: MirrorConnection = new MirrorConnection(
+          mirrorPath,
+          handshakePayload,
+          () => {
+            if (this.mirrors.get(index) === newMirror) this.mirrors.delete(index)
+          }
         )
+        mirror = newMirror
         this.mirrors.set(index, mirror)
         if (frame.op === OP_HANDSHAKE) continue // handshake already sent on connect
       }