diff --git a/Jakefile b/Jakefile
index 8bd725bdd28..109398b8852 100644
--- a/Jakefile
+++ b/Jakefile
@@ -133,8 +133,7 @@ function concatenateFiles(destinationFile, sourceFiles) {
     fs.renameSync(temp, destinationFile);
 }
 
-var useDebugMode = false;
-var emitReverseMapping = false;
+var useDebugMode = true;
 var generateDeclarations = false;
 var host = (process.env.host || process.env.TYPESCRIPT_HOST || "node");
 var compilerFilename = "tsc.js";
@@ -154,14 +153,11 @@ function compileFile(outFile, sources, prereqs, prefixes, useBuiltCompiler, noOu
             options += "--declaration ";
         }
 
-        if (emitReverseMapping) {
+        if (useDebugMode) {
             options += "--preserveConstEnums ";
         }
         
         var cmd = host + " " + dir + compilerFilename + " " + options + " ";
-        if (useDebugMode) {
-            cmd = cmd + " " + path.join(harnessDirectory, "external/es5compat.ts") + " " + path.join(harnessDirectory, "external/json2.ts") + " ";
-        }
         cmd = cmd + sources.join(" ") + (!noOutFile ? " -out " + outFile : "");
         if (useDebugMode) {
             cmd = cmd + " -sourcemap -mapRoot file:///" + path.resolve(path.dirname(outFile));
@@ -263,14 +259,9 @@ task("local", ["generate-diagnostics", "lib", tscFile, servicesFile]);
 
 
 // Local target to build the compiler and services
-desc("Emit debug mode files with sourcemaps");
-task("debug", ["emitReverseMapping"], function() {
-    useDebugMode = true;
-});
-
-desc("Emit reverse mapping for const enums");
-task("emitReverseMapping", function() {
-    emitReverseMapping = true;
+desc("Sets release mode flag");
+task("release", function() {
+    useDebugMode = false;
 });
 
 // Set the default task to "local"
@@ -321,7 +312,7 @@ task("generate-spec", [specMd])
 
 // Makes a new LKG. This target does not build anything, but errors if not all the outputs are present in the built/local directory
 desc("Makes a new LKG out of the built js files");
-task("LKG", libraryTargets, function() {
+task("LKG", ["clean", "release", "local"].concat(libraryTargets), function() {
     var expectedFiles = [tscFile, servicesFile].concat(libraryTargets);
     var missingFiles = expectedFiles.filter(function (f) {
         return !fs.existsSync(f);