diff --git a/lib/Minilisp.pm b/lib/Minilisp.pm
index dbd3b3c..50515b8 100644
--- a/lib/Minilisp.pm
+++ b/lib/Minilisp.pm
@@ -21,7 +21,11 @@ sub tokenize {
 
   while ($str)
     {
-      if ($str =~ s/^\(//)
+      if ($str =~ s/^;.*\n//)
+        {
+          # Comment. do nothing
+        }
+      elsif ($str =~ s/^\(//)
         {
           push @tokens, { type => LPAREN };
         }