diff --git a/src/main/java/com/github/nkzawa/engineio/client/Socket.java b/src/main/java/com/github/nkzawa/engineio/client/Socket.java
index d679bea..1bae0b1 100644
--- a/src/main/java/com/github/nkzawa/engineio/client/Socket.java
+++ b/src/main/java/com/github/nkzawa/engineio/client/Socket.java
@@ -94,7 +94,7 @@ public class Socket extends Emitter {
      */
     public static final int protocol = Parser.protocol;
 
-    public static boolean priorWebsocketSuccess = false;
+    private static boolean priorWebsocketSuccess = false;
 
     private static SSLContext defaultSSLContext;