diff --git a/lib/asn1.js b/lib/asn1.js
index 36cf592..83a28b3 100644
--- a/lib/asn1.js
+++ b/lib/asn1.js
@@ -153,7 +153,7 @@ ASN1._stringify = function(asn1) {
 ASN1.tpl = function (asn1) {
   //console.log(JSON.stringify(asn1, null, 2));
   //console.log(asn1);
-  var ws = '';
+  var ws = '\t';
   var i = 0;
   var vars = [];
   var str = ws;
@@ -177,12 +177,12 @@ ASN1.tpl = function (asn1) {
       if (0x05 !== asn1.type) {
         if (0x06 !== asn1.type) {
           val = Buffer.from(asn1.value || '');
-          vars.push("// 0x" + Enc.numToHex(val.byteLength) + " (" + val.byteLength + " bytes)\nvar tpl" + i + " = '"
+          vars.push("// 0x" + Enc.numToHex(val.byteLength) + " (" + val.byteLength + " bytes)\nopts.tpl" + i + " = '"
           + Enc.bufToHex(val) + "';");
           if (0x02 !== asn1.type && 0x03 !== asn1.type) {
             str += ", ";
           }
-          str += "tpl" + i;
+          str += "opts.tpl" + i;
         } else {
           str += ", " + Enc.bufToHex(asn1.value);
         }
@@ -200,8 +200,12 @@ ASN1.tpl = function (asn1) {
   }
 
   write(asn1);
+  console.log('var opts = {};');
   console.log(vars.join('\n') + '\n');
-  console.log(str + ';');
+  console.log();
+  console.log('function buildSchema(opts) {');
+  console.log('\treturn ' + str.slice(3) + ';');
+  console.log('}');
 };
 
 module.exports = ASN1;