diff --git a/CAS.h b/CAS.h
index 1308050..5fc83fc 100644
--- a/CAS.h
+++ b/CAS.h
@@ -1,5 +1,5 @@
-#ifndef _CAS_H
-#define _CAS_H
+#ifndef CAS_H
+#define CAS_H
 
 #include <stddef.h>
 
diff --git a/iob.h b/iob.h
index 585ddee..0d7014b 100644
--- a/iob.h
+++ b/iob.h
@@ -1,6 +1,6 @@
 /* this header file comes from libowfat, http://www.fefe.de/libowfat/ */
-#ifndef _IOB_H
-#define _IOB_H
+#ifndef IOB_H
+#define IOB_H
 
 /* These functions can be used to create a queue of small (or large)
  * buffers and parts of files to be sent out over a socket.  It is meant
diff --git a/isset.h b/isset.h
index 02699cc..cce257a 100644
--- a/isset.h
+++ b/isset.h
@@ -1,6 +1,6 @@
 /* this header file comes from libowfat, http://www.fefe.de/libowfat/ */
-#ifndef _ISSET_H
-#define _ISSET_H
+#ifndef ISSET_H
+#define ISSET_H
 
 /*
  How to check whether a preprocessor symbol is defined or not?
diff --git a/safemult.h b/safemult.h
index c63ee62..a6f3417 100644
--- a/safemult.h
+++ b/safemult.h
@@ -1,6 +1,6 @@
 /* this header file comes from libowfat, http://www.fefe.de/libowfat/ */
-#ifndef _SAFEMULT_H
-#define _SAFEMULT_H
+#ifndef SAFEMULT_H
+#define SAFEMULT_H
 
 #include "uint16.h"
 #include "uint32.h"
diff --git a/uint16.h b/uint16.h
index e1479ac..53c6d1c 100644
--- a/uint16.h
+++ b/uint16.h
@@ -18,11 +18,11 @@ static inline void uint16_pack(char* out,uint16 in) {
 }
 
 static inline void uint16_unpack(const char *in,uint16* out) {
-  *out=*(uint16*)in;
+  *out=*(const uint16*)in;
 }
 
 static inline uint16 uint16_read(const char* in) {
-  return *(uint16*)in;
+  return *(const uint16*)in;
 }
 
 void uint16_pack_big(char *out,uint16 in);
diff --git a/uint32.h b/uint32.h
index fc775e2..eb3f6cc 100644
--- a/uint32.h
+++ b/uint32.h
@@ -18,11 +18,11 @@ static inline void uint32_pack(char* out,uint32 in) {
 }
 
 static inline void uint32_unpack(const char *in,uint32* out) {
-  *out=*(uint32*)in;
+  *out=*(const uint32*)in;
 }
 
 static inline uint32 uint32_read(const char* in) {
-  return *(uint32*)in;
+  return *(const uint32*)in;
 }
 
 void uint32_pack_big(char *out,uint32 in);