diff --git a/ChangeLog b/ChangeLog
index 6eb6dcab..8fbed5a0 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2009-04-28  Nicolas François  <nicolas.francois@centraliens.net>
+
+	* lib/defines.h: Include <utmpx.h> and <utmp.h> to define
+	USER_NAME_MAX_LENGTH.
+
 2009-04-28  Nicolas François  <nicolas.francois@centraliens.net>
 
 	* src/login.c: Change a snprintf() to strncpy(). There are no
diff --git a/lib/defines.h b/lib/defines.h
index 3d44bb6e..adf6c20d 100644
--- a/lib/defines.h
+++ b/lib/defines.h
@@ -367,8 +367,10 @@ extern char *strerror ();
 
 /* Maximum length of usernames */
 #ifdef HAVE_UTMPX_H
+# include <utmpx.h>
 # define USER_NAME_MAX_LENGTH (sizeof (((struct utmpx *)NULL)->ut_user))
 #else
+# include <utmp.h>
 # ifdef HAVE_STRUCT_UTMP_UT_USER
 #  define USER_NAME_MAX_LENGTH (sizeof (((struct utmp *)NULL)->ut_user))
 # else