--- a/node-server/src/index.js
+++ b/node-server/src/index.js
@@ -415,6 +415,13 @@ class Match {
     this._broadcast({ type: 'opponent.status', status: 'disconnected' }, opponentSide);
   }
 
+  onPing(userId, rttMs) {
+    const side = this._sideOf(userId);
+    if (!side) return;
+    const opponentSide = side === 'left' ? 'right' : 'left';
+    // Forward sender's measured rtt to the opponent so they can display ping quality
+    this._broadcast({ type: 'opponent.ping', pingMs: rttMs }, opponentSide);
+  }
 
   tick() {
     if (this._ended) return;
