diff --git a/lib/command_line.js b/lib/command_line.js
index 3fd507ea..f48acc1f 100644
--- a/lib/command_line.js
+++ b/lib/command_line.js
@@ -78,7 +78,7 @@
   // Compile a single source script, containing the given code, according to the
   // requested options. Both compile_scripts and watch_scripts share this method.
   compile_script = function compile_script(source, code) {
-    var js, o;
+    var __dirname, __filename, js, o;
     o = options;
     try {
       if (o.tokens) {
@@ -94,6 +94,8 @@
         } else if (o.print || o.eval) {
           return print(js);
         } else {
+          __filename = source;
+          __dirname = path.dirname(source);
           return eval(js);
         }
       }
diff --git a/lib/lexer.js b/lib/lexer.js
index 7d0883dd..2db0056e 100644
--- a/lib/lexer.js
+++ b/lib/lexer.js
@@ -6,7 +6,8 @@
     this.exports = this;
     Rewriter = this.Rewriter;
   }
-  // Constants ============================================================
+  // Constants
+  // ---------
   // Keywords that CoffeScript shares in common with JS.
   JS_KEYWORDS = ["if", "else", "true", "false", "new", "return", "try", "catch", "finally", "throw", "break", "continue", "for", "in", "while", "delete", "instanceof", "typeof", "switch", "super", "extends", "class"];
   // CoffeeScript-only keywords -- which we're more relaxed about allowing.
@@ -110,7 +111,8 @@
       }
       return this.literal_token();
     };
-    // Tokenizers ==========================================================
+    // Tokenizers
+    // ----------
     // Matches identifying literals: variables, keywords, method names, etc.
     Lexer.prototype.identifier_token = function identifier_token() {
       var id, tag;
@@ -313,7 +315,8 @@
       this.i += value.length;
       return true;
     };
-    // Token Manipulators ==================================================
+    // Token Manipulators
+    // ------------------
     // As we consume a new IDENTIFIER, look at the previous token to determine
     // if it's a special kind of access.
     Lexer.prototype.name_access_type = function name_access_type() {
@@ -344,7 +347,8 @@
     Lexer.prototype.assignment_error = function assignment_error() {
       throw new Error('SyntaxError: Reserved word "' + this.value() + '" on line ' + this.line + ' can\'t be assigned');
     };
-    // Helpers =============================================================
+    // Helpers
+    // -------
     // Add a token to the results, taking note of the line number.
     Lexer.prototype.token = function token(tag, value) {
       return this.tokens.push([tag, value, this.line]);
diff --git a/src/command_line.coffee b/src/command_line.coffee
index f322559f..298fac82 100644
--- a/src/command_line.coffee
+++ b/src/command_line.coffee
@@ -80,7 +80,10 @@ compile_script: (source, code) ->
       if      o.compile         then write_js source, js
       else if o.lint            then lint js
       else if o.print or o.eval then print js
-      else                           eval js
+      else
+        __filename: source
+        __dirname:  path.dirname source
+        eval js
   catch err
     if o.watch                  then puts err.message else throw err
 
diff --git a/src/lexer.coffee b/src/lexer.coffee
index 60f81974..4392d197 100644
--- a/src/lexer.coffee
+++ b/src/lexer.coffee
@@ -4,7 +4,8 @@ else
   this.exports: this
   Rewriter: this.Rewriter
 
-# Constants ============================================================
+# Constants
+# ---------
 
 # Keywords that CoffeScript shares in common with JS.
 JS_KEYWORDS: [
@@ -115,7 +116,8 @@ exports.Lexer: class Lexer
     return if @whitespace_token()
     return    @literal_token()
 
-  # Tokenizers ==========================================================
+  # Tokenizers
+  # ----------
 
   # Matches identifying literals: variables, keywords, method names, etc.
   identifier_token: ->
@@ -261,7 +263,8 @@ exports.Lexer: class Lexer
     @i += value.length
     true
 
-  # Token Manipulators ==================================================
+  # Token Manipulators
+  # ------------------
 
   # As we consume a new IDENTIFIER, look at the previous token to determine
   # if it's a special kind of access.
@@ -290,7 +293,8 @@ exports.Lexer: class Lexer
   assignment_error: ->
     throw new Error 'SyntaxError: Reserved word "' + @value() + '" on line ' + @line + ' can\'t be assigned'
 
-  # Helpers =============================================================
+  # Helpers
+  # -------
 
   # Add a token to the results, taking note of the line number.
   token: (tag, value) ->