diff --git a/left/src/slave_protocol_handler.h b/left/src/slave_protocol_handler.h
index 3478b87..fecadb3 100644
--- a/left/src/slave_protocol_handler.h
+++ b/left/src/slave_protocol_handler.h
@@ -1,5 +1,5 @@
-#ifndef __SLAVE_PROTOCOL_HANDLER__
-#define __SLAVE_PROTOCOL_HANDLER__
+#ifndef __SLAVE_PROTOCOL_HANDLER_H__
+#define __SLAVE_PROTOCOL_HANDLER_H__
 
 // Includes: