diff --git a/src/WebSocketsClient.cpp b/src/WebSocketsClient.cpp
index 91fee1d..e0019fd 100644
--- a/src/WebSocketsClient.cpp
+++ b/src/WebSocketsClient.cpp
@@ -63,6 +63,7 @@ void WebSocketsClient::begin(const char *host, uint16_t port, const char * url,
     _client.cVersion = 0;
     _client.base64Authorization = "";
     _client.plainAuthorization = "";
+    _client.isSocketIO = false;
 
 #ifdef ESP8266
     randomSeed(RANDOM_REG32);