diff --git a/include/polarssl/md4.h b/include/polarssl/md4.h
index f0a7c33..1262e01 100644
--- a/include/polarssl/md4.h
+++ b/include/polarssl/md4.h
@@ -1,8 +1,8 @@
 /**
  * \file md4.h
  */
-#ifndef XYSSL_MD4_H
-#define XYSSL_MD4_H
+#ifndef POLARSSL_MD4_H
+#define POLARSSL_MD4_H
 
 /**
  * \brief          MD4 context structure