diff --git a/src/network/Client.ts b/src/network/Client.ts
index 6f290e8..f22e05c 100644
--- a/src/network/Client.ts
+++ b/src/network/Client.ts
@@ -29,16 +29,21 @@ export abstract class Client extends EventEmitter {
           this.metadata.name = data.newname;
         }
 
-        let idx = this.players.indexOf(data.oldname);
-        if (idx < 0) {
-          // Weird
-          console.warn(
-            `Someone (${data.oldname}) changed name but wasn't on the player list`
-          );
-          this.players.push(data.newname);
-          break;
+        // Only mutate player list if we have one
+        // This is because rename messages can be received during the initial
+        // handshake, to signal a forced name change before joining.
+        if (this.players) {
+          let idx = this.players.indexOf(data.oldname);
+          if (idx < 0) {
+            // Weird
+            console.warn(
+              `Someone (${data.oldname}) changed name but wasn't on the player list`
+            );
+            this.players.push(data.newname);
+            break;
+          }
+          Vue.set(this.players, idx, data.newname);
         }
-        Vue.set(this.players, idx, data.newname);
         this.emit("rename", data.oldname, data.newname);
         break;
       // A new player joined the room (this includes us)