diff --git a/ChangeLog b/ChangeLog
index 910d02f1..acee091b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2013-08-15  Nicolas François  <nicolas.francois@centraliens.net>
+
+	* src/usermod.c: Fix parse of ranges. The hyphen might be followed
+	by a negative integer.
+
 2013-08-15  Nicolas François  <nicolas.francois@centraliens.net>
 
 	* lib/subordinateio.c (find_free_range): max is allowed for new
diff --git a/src/usermod.c b/src/usermod.c
index 250ac1a7..5f5838dc 100644
--- a/src/usermod.c
+++ b/src/usermod.c
@@ -336,7 +336,7 @@ struct ulong_range
 static struct ulong_range getulong_range(const char *str)
 {
 	struct ulong_range result = { .first = ULONG_MAX, .last = 0 };
-	unsigned long long first, last;
+	long long first, last;
 	char *pos;
 
 	errno = 0;
@@ -346,7 +346,7 @@ static struct ulong_range getulong_range(const char *str)
 		goto out;
 
 	errno = 0;
-	last = strtoul(pos + 1, &pos, 10);
+	last = strtoll(pos + 1, &pos, 10);
 	if (('\0' != *pos ) || (ERANGE == errno) ||
 	    (last != (unsigned long int)last))
 		goto out;