diff --git a/lib/fugit/nat.rb b/lib/fugit/nat.rb
index e11563e..400e6fe 100644
--- a/lib/fugit/nat.rb
+++ b/lib/fugit/nat.rb
@@ -54,7 +54,7 @@ module Parser include Raabro
         %w[ zero ] + one_to_nine +
         %w[ ten eleven twelve thirteen fourteen fifteen sixteen seventeen
             eighteen nineteen ] +
-          %w[ twenty thirty fourty fifty ]
+          %w[ twenty thirty forty fifty ]
             .collect { |a|
               ([ nil ] + one_to_nine)
                 .collect { |b| [ a, b ].compact.join('-') } }
diff --git a/spec/nat_spec.rb b/spec/nat_spec.rb
index a7c2c50..c09f651 100644
--- a/spec/nat_spec.rb
+++ b/spec/nat_spec.rb
@@ -169,8 +169,9 @@
         'every year at 20:10' => '10 20 1 1 *',
 
         'every day at zero dark twenty' => '20 0 * * *',
+        'every day at zero dark forty' => '40 0 * * *',
+        'every day at oh dark forty' => '40 0 * * *',
         'every day at one dark fifty' => '50 1 * * *',
-        #'every day at oh dark fourty' => '40 0 * * *',
         'every day at noon' => '0 12 * * *',
         'every day at midnight' => '0 0 * * *',