diff --git a/src/TinyMqtt.h b/src/TinyMqtt.h
index 3246e63..2c98161 100644
--- a/src/TinyMqtt.h
+++ b/src/TinyMqtt.h
@@ -158,7 +158,7 @@ class MqttClient
 		void dump()
 		{
 			uint32_t ms=millis();
-			Serial << "MqttClient (" << clientId.c_str() << ") p=" << (int32_t) parent
+			Serial << "MqttClient (" << clientId.c_str() << ") p=" << (uint64_t) parent
 				<< " c=" << (int32_t)client << (connected() ? " ON " : " OFF"); 
 			Serial << ", alive=" << (uint32_t)alive << '/' << ms << ", ka=" << keep_alive;
 			Serial << (client && client->connected() ? "" : "dis") << "connected";