diff --git a/lib/main.js b/lib/main.js
index 61fc25e5..1e1eae9e 100644
--- a/lib/main.js
+++ b/lib/main.js
@@ -59,7 +59,6 @@ Lambda.prototype.run = function (program) {
 };
 
 Lambda.prototype._runHandler = function (handler, event, program, context) {
-
   var startTime = new Date();
   var timeout = Math.min(program.timeout, 300) * 1000; // convert the timeout into milliseconds
 
@@ -67,13 +66,12 @@ Lambda.prototype._runHandler = function (handler, event, program, context) {
     if (err) {
       console.log('Error: ' + err);
       process.exit(-1);
-    } else {
-      console.log('Success:');
-      if (result) {
-        console.log(JSON.stringify(result));
-      }
-      process.exit(0);
     }
+    console.log('Success:');
+    if (result) {
+      console.log(JSON.stringify(result));
+    }
+    process.exit(0);
   };
 
   context.getRemainingTimeInMillis = function () {
@@ -81,17 +79,11 @@ Lambda.prototype._runHandler = function (handler, event, program, context) {
     return timeout - (currentTime - startTime);
   };
 
-  switch(program.runtime) {
-    case "nodejs4.3":
-      handler(event, context, callback);
-    break;
-    case "nodejs6.10":
-      handler(event, context, callback);
-    break;
-    default:
-      console.error("Runtime [" + runtime + "] is not supported.");
+  if (['nodejs4.3', 'nodejs6.10'].indexOf(program.runtime) == -1) {
+    console.error("Runtime [" + program.runtime + "] is not supported.");
+    process.exit(-2);
   }
-
+  handler(event, context, callback);
 };
 
 Lambda.prototype._params = function (program, buffer) {
@@ -255,11 +247,9 @@ Lambda.prototype._postInstallScript = function (program, codeDirectory, callback
       callback(null);
     }
   });
-
 };
 
 Lambda.prototype._zip = function (program, codeDirectory, callback) {
-
   var options = {
     type: 'nodebuffer',
     compression: 'DEFLATE'