diff --git a/src/espmega_iot_core.cpp b/src/espmega_iot_core.cpp
index d6253ac..3477090 100644
--- a/src/espmega_iot_core.cpp
+++ b/src/espmega_iot_core.cpp
@@ -2,7 +2,10 @@
 
 // OS Configuration
 // #define FASTBOOT
+
+#ifndef ESPMEGA_REV
 #define ESPMEGA_REV "ESPMega PRO R3.3b"
+#endif
 
 // Network Connectivity
 char HOSTNAME[15];