diff --git a/tools/transpiler/index.js b/tools/transpiler/index.js
index 67e6dd4739..c8b559937a 100644
--- a/tools/transpiler/index.js
+++ b/tools/transpiler/index.js
@@ -18,6 +18,7 @@ var SELF_COMPILE_OPTIONS = {
 
 var needsReload = true;
 var oldSystemGet = System.get;
+var currentOptions;
 
 exports.reloadSources = function() {
   needsReload = true;
@@ -43,10 +44,12 @@ exports.compile = function compile(options, paths, source, reloadTraceur) {
   var CompilerCls = System.get('transpiler/src/compiler').Compiler;
 
   var compiler = new CompilerCls(options, moduleName);
+  currentOptions = options;
   var result = {
     js: compiler.compile(source, inputPath, outputPath),
     sourceMap: null
   };
+  currentOptions = null;
 
   var sourceMapString = compiler.getSourceMap();
   if (sourceMapString) {
@@ -186,6 +189,7 @@ function useRttsAssertModuleForConvertingTypesToExpressions() {
   for (var prop in patch.prototype) {
     original.prototype[prop] = patch.prototype[prop];
   }
+  original.prototype.getOptions = function() { return currentOptions; };
 
   var TypeAssertionTransformer = System.get(traceurVersion+'/src/codegeneration/TypeAssertionTransformer').TypeAssertionTransformer;
   var createIdentifierExpression = System.get(traceurVersion+'/src/codegeneration/ParseTreeFactory').createIdentifierExpression;
@@ -197,7 +201,8 @@ function useRttsAssertModuleForConvertingTypesToExpressions() {
         this.paramTypes_.atLeastOneParameterTyped = true;
       } else {
         // PATCH start
-        typeAnnotation = parseExpression(["assert.type.any"]);
+        var typeModule = currentOptions.outputLanguage === 'es6' ? 'assert' : '$traceurRuntime';
+        typeAnnotation = parseExpression([typeModule + ".type.any"]);
         // PATCH end
       }
 
diff --git a/tools/transpiler/src/patch/TypeToExpressionTransformer.js b/tools/transpiler/src/patch/TypeToExpressionTransformer.js
index 54bfe00986..d26f503022 100644
--- a/tools/transpiler/src/patch/TypeToExpressionTransformer.js
+++ b/tools/transpiler/src/patch/TypeToExpressionTransformer.js
@@ -16,9 +16,13 @@ import {
 } from 'traceur/src/codegeneration/PlaceholderParser.js';
 
 export class TypeToExpressionTransformer extends ParseTreeTransformer {
+  // Not used. Just required to call super() by traceur.
   constructor(idGenerator, reporter, options) {
     super(idGenerator, reporter);
-    this.options_ = options;
+  }
+
+  typeModule() {
+    return parseExpression([this.getOptions().outputLanguage === 'es6' ? 'assert' : '$traceurRuntime']);
   }
 
   transformTypeName(tree) {
@@ -30,18 +34,18 @@ export class TypeToExpressionTransformer extends ParseTreeTransformer {
   }
 
   transformPredefinedType(tree) {
-    return parseExpression `assert.type.${tree.typeToken})`;
+    return parseExpression `${this.typeModule()}.type.${tree.typeToken})`;
   }
 
   transformTypeReference(tree) {
     var typeName = this.transformAny(tree.typeName);
     var args = this.transformAny(tree.args);
     var argumentList = new ArgumentList(tree.location, [typeName, ...args]);
-    return parseExpression `assert.genericType(${argumentList})`;
+    return parseExpression `${this.typeModule()}.genericType(${argumentList})`;
   }
 
   transformTypeArguments(tree) {
     return this.transformList(tree.args);
   }
 
-}
\ No newline at end of file
+}