diff --git a/src/cfu.h b/src/cfu.h
index c27c1ca..63eaf28 100644
--- a/src/cfu.h
+++ b/src/cfu.h
@@ -35,8 +35,8 @@
  * OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#ifndef _LIBCFU_H_
-#define _LIBCFU_H_
+#ifndef LIBCFU_H_
+#define LIBCFU_H_
 
 #ifdef __cplusplus
 #define CFU_BEGIN_DECLS extern "C" {
diff --git a/src/cfuconf.h b/src/cfuconf.h
index 1a61324..be0e0d7 100644
--- a/src/cfuconf.h
+++ b/src/cfuconf.h
@@ -35,8 +35,8 @@
  * OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#ifndef _CFU_CONF_H_
-#define _CFU_CONF_H_
+#ifndef CFU_CONF_H_
+#define CFU_CONF_H_
 
 #include <cfu.h>
 #include <cfuhash.h>
diff --git a/src/cfuhash.h b/src/cfuhash.h
index 418f452..e956179 100644
--- a/src/cfuhash.h
+++ b/src/cfuhash.h
@@ -35,8 +35,8 @@
  * OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#ifndef _CFU_HASH_H_
-#define _CFU_HASH_H_
+#ifndef CFU_HASH_H_
+#define CFU_HASH_H_
 
 #include <cfu.h>
 #include <stdio.h>
diff --git a/src/cfulist.h b/src/cfulist.h
index 165885b..509d3c2 100644
--- a/src/cfulist.h
+++ b/src/cfulist.h
@@ -35,8 +35,8 @@
  * OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#ifndef _CFU_LIST_
-#define _CFU_LIST_
+#ifndef CFU_LIST_
+#define CFU_LIST_
 
 #include <cfu.h>
 #include <stddef.h>
diff --git a/src/cfuopt.h b/src/cfuopt.h
index 2dda595..82cd5c5 100644
--- a/src/cfuopt.h
+++ b/src/cfuopt.h
@@ -37,8 +37,8 @@
 
 #include <cfu.h>
 
-#ifndef _CFU_OPT_H_
-#define _CFU_OPT_H_
+#ifndef CFU_OPT_H_
+#define CFU_OPT_H_
 
 CFU_BEGIN_DECLS
 
diff --git a/src/cfustring.h b/src/cfustring.h
index 562fea5..cfc718e 100644
--- a/src/cfustring.h
+++ b/src/cfustring.h
@@ -35,8 +35,8 @@
  * OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#ifndef _CFU_STRING_H_
-#define _CFU_STRING_H_
+#ifndef CFU_STRING_H_
+#define CFU_STRING_H_
 
 #include <cfu.h>
 #include <stdarg.h>
diff --git a/src/cfuthread_queue.h b/src/cfuthread_queue.h
index f9feabc..577fea9 100644
--- a/src/cfuthread_queue.h
+++ b/src/cfuthread_queue.h
@@ -35,8 +35,8 @@
  * OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#ifndef _CFUTHREAD_QUEUE_H
-#define _CFUTHREAD_QUEUE_H
+#ifndef CFUTHREAD_QUEUE_H
+#define CFUTHREAD_QUEUE_H
 
 #include <cfu.h>
 
diff --git a/src/cfutime.h b/src/cfutime.h
index 48fae9c..ae34466 100644
--- a/src/cfutime.h
+++ b/src/cfutime.h
@@ -35,8 +35,8 @@
  * OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#ifndef _CFU_TIME_H_
-#define _CFU_TIME_H_
+#ifndef CFU_TIME_H_
+#define CFU_TIME_H_
 
 #include <cfu.h>