diff --git a/lib/coffee-script/coffee-script.js b/lib/coffee-script/coffee-script.js
index 54dd818c..8feaf58d 100644
--- a/lib/coffee-script/coffee-script.js
+++ b/lib/coffee-script/coffee-script.js
@@ -1,6 +1,6 @@
 // Generated by CoffeeScript 1.5.0
 (function() {
-  var Lexer, baseFileName, compile, count, ext, extensions, fs, lexer, loadFile, parser, path, sourcemap, vm, _i, _len,
+  var Lexer, baseFileName, compile, count, ext, extend, extensions, fs, lexer, loadFile, parser, path, sourcemap, vm, _i, _len, _ref,
     __indexOf = [].indexOf || function(item) { for (var i = 0, l = this.length; i < l; i++) { if (i in this && this[i] === item) return i; } return -1; },
     __hasProp = {}.hasOwnProperty;
 
@@ -16,7 +16,7 @@
 
   vm = require('vm');
 
-  count = require('./helpers').count;
+  _ref = require('./helpers'), count = _ref.count, extend = _ref.extend;
 
   extensions = ['.coffee', '.litcoffee'];
 
@@ -85,18 +85,23 @@
   };
 
   exports.compileWithSourceMap = function(code, options) {
-    var coffeeFile, js, jsFile, map, merge;
+    var coffeeFile, compiledJs, jsFile, merge, v3SourceMap;
     if (options == null) {
       options = {};
     }
     merge = exports.helpers.merge;
     try {
+      options = extend({}, options);
       options.sourceMap = new sourcemap.SourceMap();
       coffeeFile = path.basename(options.filename);
       jsFile = baseFileName(options.filename) + ".js";
-      js = exports.compile(code, options);
-      map = sourcemap.generateV3SourceMap(options.sourceMap, coffeeFile, jsFile);
-      return [js, map];
+      compiledJs = exports.compile(code, options);
+      v3SourceMap = sourcemap.generateV3SourceMap(options.sourceMap, coffeeFile, jsFile);
+      return {
+        compiledJs: compiledJs,
+        v3SourceMap: v3SourceMap,
+        sourceMap: options.sourceMap
+      };
     } catch (err) {
       if (options.filename) {
         err.message = "In " + options.filename + ", " + err.message;
@@ -118,7 +123,7 @@
   };
 
   exports.run = function(code, options) {
-    var mainModule, _ref;
+    var mainModule, _ref1;
     if (options == null) {
       options = {};
     }
@@ -126,7 +131,7 @@
     mainModule.filename = process.argv[1] = options.filename ? fs.realpathSync(options.filename) : '.';
     mainModule.moduleCache && (mainModule.moduleCache = {});
     mainModule.paths = require('module')._nodeModulePaths(path.dirname(fs.realpathSync(options.filename)));
-    if ((_ref = path.extname(mainModule.filename), __indexOf.call(extensions, _ref) < 0) || require.extensions) {
+    if ((_ref1 = path.extname(mainModule.filename), __indexOf.call(extensions, _ref1) < 0) || require.extensions) {
       return mainModule._compile(compile(code, options), mainModule.filename);
     } else {
       return mainModule._compile(code, mainModule.filename);
@@ -134,7 +139,7 @@
   };
 
   exports["eval"] = function(code, options) {
-    var Module, Script, js, k, o, r, sandbox, v, _j, _len1, _module, _ref, _ref1, _require;
+    var Module, Script, js, k, o, r, sandbox, v, _j, _len1, _module, _ref1, _ref2, _require;
     if (options == null) {
       options = {};
     }
@@ -148,10 +153,10 @@
           sandbox = options.sandbox;
         } else {
           sandbox = Script.createContext();
-          _ref = options.sandbox;
-          for (k in _ref) {
-            if (!__hasProp.call(_ref, k)) continue;
-            v = _ref[k];
+          _ref1 = options.sandbox;
+          for (k in _ref1) {
+            if (!__hasProp.call(_ref1, k)) continue;
+            v = _ref1[k];
             sandbox[k] = v;
           }
         }
@@ -168,9 +173,9 @@
           return Module._load(path, _module, true);
         };
         _module.filename = sandbox.__filename;
-        _ref1 = Object.getOwnPropertyNames(require);
-        for (_j = 0, _len1 = _ref1.length; _j < _len1; _j++) {
-          r = _ref1[_j];
+        _ref2 = Object.getOwnPropertyNames(require);
+        for (_j = 0, _len1 = _ref2.length; _j < _len1; _j++) {
+          r = _ref2[_j];
           if (r !== 'paths') {
             _require[r] = require[r];
           }
diff --git a/lib/coffee-script/command.js b/lib/coffee-script/command.js
index bb83ee71..98509092 100644
--- a/lib/coffee-script/command.js
+++ b/lib/coffee-script/command.js
@@ -152,7 +152,7 @@
   };
 
   compileScript = function(file, input, base) {
-    var o, options, t, task, _ref1;
+    var compiled, o, options, t, task;
     o = opts;
     options = compileOptions(file);
     try {
@@ -173,7 +173,9 @@
         return compileJoin();
       } else {
         if (o.maps) {
-          _ref1 = CoffeeScript.compileWithSourceMap(t.input, t.options), t.output = _ref1[0], t.sourceMap = _ref1[1];
+          compiled = CoffeeScript.compileWithSourceMap(t.input, t.options);
+          t.output = compiled.compiledJs;
+          t.sourceMap = compiled.v3SourceMap;
         } else {
           t.output = CoffeeScript.compile(t.input, t.options);
         }
diff --git a/src/coffee-script.coffee b/src/coffee-script.coffee
index 44ae9a1d..d7c4700c 100644
--- a/src/coffee-script.coffee
+++ b/src/coffee-script.coffee
@@ -12,7 +12,7 @@ path        = require 'path'
 {parser}    = require './parser'
 sourcemap   = require './sourcemap'
 vm          = require 'vm'
-{count}     = require './helpers'
+{count, extend} = require './helpers'
 
 # The file extensions that are considered to be CoffeeScript.
 extensions = ['.coffee', '.litcoffee']
@@ -70,17 +70,23 @@ exports.compile = compile = (code, options = {}) ->
   "// #{header}\n#{js}"
 
 # Generates a compiled code and a source map for a string of CoffeeScript code.
-# Callers should specifiy `options.filename`.  Returns a `[sourcemap, compiledCode]` pair, where
-# sourcemap is a v3 source map.
+# Callers should specifiy `options.filename`.  Returns a `{compiledJs, v3SourceMap, sourceMap}
+# object, where sourceMap is a sourcemap.coffee#SourceMap object, handy for doing programatic
+# lookups.
 exports.compileWithSourceMap = (code, options={}) ->
   {merge} = exports.helpers
   try
+    options = extend {}, options
     options.sourceMap = new sourcemap.SourceMap()
     coffeeFile = path.basename options.filename
     jsFile = baseFileName(options.filename) + ".js"
-    js = exports.compile code, options
-    map = sourcemap.generateV3SourceMap options.sourceMap, coffeeFile, jsFile
-    return [js, map]
+    compiledJs = exports.compile code, options
+    v3SourceMap = sourcemap.generateV3SourceMap options.sourceMap, coffeeFile, jsFile
+    return {
+      compiledJs,
+      v3SourceMap,
+      sourceMap: options.sourceMap
+    }
   catch err
     err.message = "In #{options.filename}, #{err.message}" if options.filename
     throw err
diff --git a/src/command.coffee b/src/command.coffee
index 3c596331..f7ee39fb 100644
--- a/src/command.coffee
+++ b/src/command.coffee
@@ -127,7 +127,9 @@ compileScript = (file, input, base) ->
       compileJoin()
     else
       if o.maps
-        [t.output, t.sourceMap] = CoffeeScript.compileWithSourceMap t.input, t.options
+        compiled = CoffeeScript.compileWithSourceMap t.input, t.options
+        t.output = compiled.compiledJs
+        t.sourceMap = compiled.v3SourceMap
       else
         t.output = CoffeeScript.compile t.input, t.options