diff --git a/ChangeLog b/ChangeLog
index 0f2efd76..cf986512 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2008-05-26  Nicolas François  <nicolas.francois@centraliens.net>
+
+	* lib/pwio.h: Add protection against multiple inclusions.
+	* lib/pwio.c: The changed, isopen, locked, and readonly fields
+	of the db are booleans.
+
 2008-05-26  Nicolas François  <nicolas.francois@centraliens.net>
 
 	* lib/shadowio.h, lib/shadowio.c: spw_file_present returns a bool.
diff --git a/lib/pwio.c b/lib/pwio.c
index 820467c0..f36fec22 100644
--- a/lib/pwio.c
+++ b/lib/pwio.c
@@ -102,10 +102,10 @@ static struct commonio_db passwd_db = {
 	NULL,			/* head */
 	NULL,			/* tail */
 	NULL,			/* cursor */
-	0,			/* changed */
-	0,			/* isopen */
-	0,			/* locked */
-	0			/* readonly */
+	false,			/* changed */
+	false,			/* isopen */
+	false,			/* locked */
+	false			/* readonly */
 };
 
 int pw_name (const char *filename)
diff --git a/lib/pwio.h b/lib/pwio.h
index bc662e2d..12a0e63f 100644
--- a/lib/pwio.h
+++ b/lib/pwio.h
@@ -31,6 +31,10 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
+/* $Id$ */
+#ifndef _PWIO_H
+#define _PWIO_H
+
 #include <pwd.h>
 extern int pw_close (void);
 extern const struct passwd *pw_locate (const char *);
@@ -45,3 +49,4 @@ extern int pw_unlock (void);
 extern int pw_update (const struct passwd *);
 extern int pw_sort (void);
 
+#endif