diff --git a/lib/libc/iconv/citrus_csmapper.h b/lib/libc/iconv/citrus_csmapper.h
index dd178da90cf..389ad431e17 100644
--- a/lib/libc/iconv/citrus_csmapper.h
+++ b/lib/libc/iconv/citrus_csmapper.h
@@ -28,7 +28,7 @@
  */
 
 #ifndef _CITRUS_CSMAPPER_H_
-#define _CITRUS_CSMAPPER_H
+#define _CITRUS_CSMAPPER_H_
 
 #define _citrus_csmapper		_citrus_mapper
 #define _citrus_csmapper_close		_citrus_mapper_close