diff --git a/lib/fugit/nat.rb b/lib/fugit/nat.rb
index abdf74d..07afd95 100644
--- a/lib/fugit/nat.rb
+++ b/lib/fugit/nat.rb
@@ -691,8 +691,10 @@ def parse_cron(hm, opts)
         a << tz.data0 if tz
         a.shift if a.first == [ '0' ]
 
+        letters_first = ->(x) { x.is_a?(Numeric) ? x : 0 }
+
         s = a
-          .collect { |e| e.uniq.sort.collect(&:to_s).join(',') }
+          .collect { |e| e.uniq.sort_by(&letters_first).collect(&:to_s).join(',') }
           .join(' ')
 
         c = Fugit::Cron.parse(s)
diff --git a/spec/nat_spec.rb b/spec/nat_spec.rb
index 6caf40f..5e17edb 100644
--- a/spec/nat_spec.rb
+++ b/spec/nat_spec.rb
@@ -67,6 +67,8 @@
         'every month on the 1st and 2nd at 12:00 pm' => '0 12 1,2 * *',
         'every month on the 1st and the 2nd at 12:00 pm' => '0 12 1,2 * *',
         'every month on the 1st and the second at 12:00 pm' => '0 12 1,2 * *',
+        'every month on the 1st and last at 12:00 pm' => '0 12 L,1 * *',
+        'every month on the 1st and the last at 12:00 pm' => '0 12 L,1 * *',
           #
           # gh-57, 12pm --> noon