diff --git a/src/defines.h b/src/defines.h
index 36949daf..edbc4aed 100644
--- a/src/defines.h
+++ b/src/defines.h
@@ -85,9 +85,9 @@ union serial_u {
 #define DEVNAME_LEN             16
 #define NTP_ADDR_LEN            32 // DNS Name
 
-#define MQTT_ADDR_LEN           32 // DNS Name
-#define MQTT_USER_LEN           16
-#define MQTT_PWD_LEN            32
+#define MQTT_ADDR_LEN           64 // DNS Name
+#define MQTT_USER_LEN           64
+#define MQTT_PWD_LEN            64
 #define MQTT_TOPIC_LEN          64
 
 #define MQTT_MAX_PACKET_SIZE    384