diff --git a/arch/mips/jz4740/serial.h b/arch/mips/jz4740/serial.h
index b9fe3ad..aa5a939 100644
--- a/arch/mips/jz4740/serial.h
+++ b/arch/mips/jz4740/serial.h
@@ -14,6 +14,7 @@
  */
 
 #ifndef __MIPS_JZ4740_SERIAL_H__
+#define __MIPS_JZ4740_SERIAL_H__
 
 void jz4740_serial_out(struct uart_port *p, int offset, int value);