diff --git a/ChangeLog b/ChangeLog
index 5a1bed90..660fc56c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2010-03-21  Nicolas François  <nicolas.francois@centraliens.net>
+
+	* libmisc/find_new_gid.c, libmisc/find_new_uid.c: Detect some
+	misconfigurations of UID_MIN, UID_MAX, SYS_UID_MIN, SYS_UID_MAX (and
+	the GID equivalents)
+
 2010-03-20  Nicolas François  <nicolas.francois@centraliens.net>
 
 	* NEWS, configure.in: Next version will be 4.1.5.
diff --git a/libmisc/find_new_gid.c b/libmisc/find_new_gid.c
index 19bc1966..1c08b9b4 100644
--- a/libmisc/find_new_gid.c
+++ b/libmisc/find_new_gid.c
@@ -60,10 +60,20 @@ int find_new_gid (bool sys_group,
 	if (!sys_group) {
 		gid_min = (gid_t) getdef_ulong ("GID_MIN", 1000UL);
 		gid_max = (gid_t) getdef_ulong ("GID_MAX", 60000UL);
+		if (gid_max < gid_min) {
+			(void) fprintf (stderr,
+			                _("%s: Invalid configuration: GID_MIN (%lu), GID_MAX (%lu)\n"),
+			                Prog, (unsigned long) gid_min, (unsigned long) gid_max);
+		}
 	} else {
 		gid_min = (gid_t) getdef_ulong ("SYS_GID_MIN", 101UL);
 		gid_max = (gid_t) getdef_ulong ("GID_MIN", 1000UL) - 1;
 		gid_max = (gid_t) getdef_ulong ("SYS_GID_MAX", (unsigned long) gid_max);
+		if (gid_max < gid_min) {
+			(void) fprintf (stderr,
+			                _("%s: Invalid configuration: SYS_GID_MIN (%lu), GID_MIN (%lu), SYS_GID_MAX (%lu)\n"),
+			                Prog, (unsigned long) gid_min, getdef_ulong ("GID_MIN", 1000UL), (unsigned long) gid_max);
+		}
 	}
 	used_gids = alloca (sizeof (bool) * (gid_max +1));
 	memset (used_gids, false, sizeof (bool) * (gid_max + 1));
diff --git a/libmisc/find_new_uid.c b/libmisc/find_new_uid.c
index b1a188af..139fe5f8 100644
--- a/libmisc/find_new_uid.c
+++ b/libmisc/find_new_uid.c
@@ -60,10 +60,20 @@ int find_new_uid (bool sys_user,
 	if (!sys_user) {
 		uid_min = (uid_t) getdef_ulong ("UID_MIN", 1000UL);
 		uid_max = (uid_t) getdef_ulong ("UID_MAX", 60000UL);
+		if (uid_max < uid_min) {
+			(void) fprintf (stderr,
+			                _("%s: Invalid configuration: UID_MIN (%lu), UID_MAX (%lu)\n"),
+			                Prog, (unsigned long) uid_min, (unsigned long) uid_max);
+		}
 	} else {
 		uid_min = (uid_t) getdef_ulong ("SYS_UID_MIN", 101UL);
 		uid_max = (uid_t) getdef_ulong ("UID_MIN", 1000UL) - 1;
 		uid_max = (uid_t) getdef_ulong ("SYS_UID_MAX", (unsigned long) uid_max);
+		if (uid_max < uid_min) {
+			(void) fprintf (stderr,
+			                _("%s: Invalid configuration: SYS_UID_MIN (%lu), UID_MIN (%lu), SYS_UID_MAX (%lu)\n"),
+			                Prog, (unsigned long) uid_min, getdef_ulong ("UID_MIN", 1000UL), (unsigned long) uid_max);
+		}
 	}
 	used_uids = alloca (sizeof (bool) * (uid_max +1));
 	memset (used_uids, false, sizeof (bool) * (uid_max + 1));