diff --git a/ChangeLog b/ChangeLog
index e352390e..0f2efd76 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2008-05-26  Nicolas François  <nicolas.francois@centraliens.net>
+
+	* lib/shadowio.h, lib/shadowio.c: spw_file_present returns a bool.
+	* lib/shadowio.h: Add protection against multiple inclusions.
+
 2008-05-26  Nicolas François  <nicolas.francois@centraliens.net>
 
 	* lib/sgroupio.c: Avoid assignments in comparisons.
diff --git a/lib/shadowio.c b/lib/shadowio.c
index fe6e7a56..bb59c20c 100644
--- a/lib/shadowio.c
+++ b/lib/shadowio.c
@@ -110,7 +110,7 @@ int spw_name (const char *filename)
 	return commonio_setname (&shadow_db, filename);
 }
 
-int spw_file_present (void)
+bool spw_file_present (void)
 {
 	return commonio_present (&shadow_db);
 }
diff --git a/lib/shadowio.h b/lib/shadowio.h
index 81267bbf..b10f51e0 100644
--- a/lib/shadowio.h
+++ b/lib/shadowio.h
@@ -30,8 +30,14 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
+/* $Id$ */
+#ifndef _SHADOWIO_H
+#define _SHADOWIO_H
+
+#include "defines.h"
+
 extern int spw_close (void);
-extern int spw_file_present (void);
+extern bool spw_file_present (void);
 extern const struct spwd *spw_locate (const char *);
 extern int spw_lock (void);
 extern int spw_name (const char *);
@@ -43,3 +49,4 @@ extern int spw_unlock (void);
 extern int spw_update (const struct spwd *);
 extern int spw_sort (void);
 
+#endif