diff --git a/index.js b/index.js
index e76e68b..47b0289 100644
--- a/index.js
+++ b/index.js
@@ -44,12 +44,13 @@ function getArgNames(ast) {
 }
 
 function preprocess(func) {
+  PREFIX_COUNTER++;
+  //Compute new prefix
+  var prefix = "_inline_" + PREFIX_COUNTER + "_"
+  
   var src = ["(", func, ")()"].join("")
   var ast = esprima.parse(src, { range: true })
   
-  //Compute new prefix
-  var prefix = "_inline_" + (PREFIX_COUNTER++) + "_"
-  
   //Parse out arguments
   var argNames = getArgNames(ast)
   var compiledArgs = new Array(argNames.length)
@@ -192,4 +193,4 @@ function preprocess(func) {
   return routine
 }
 
-module.exports = preprocess
\ No newline at end of file
+module.exports = preprocess