diff --git a/packages/y-partyserver/src/server/index.ts b/packages/y-partyserver/src/server/index.ts
index e7d1309..ada5904 100644
--- a/packages/y-partyserver/src/server/index.ts
+++ b/packages/y-partyserver/src/server/index.ts
@@ -335,10 +335,14 @@ export class YServer<Env = unknown> extends Server<Env> {
     }
   }
 
-  onMessage = handleChunked((conn, message) =>
+  private handleChunkedMessage = handleChunked((conn, message) =>
     this.handleMessage(conn, message)
   );
 
+  onMessage(conn: Connection, message: WSMessage): void {
+    this.handleChunkedMessage(conn, message);
+  }
+
   onClose(
     connection: Connection<unknown>,
     _code: number,