diff --git a/lib/coffee-script/lexer.js b/lib/coffee-script/lexer.js
index 5a078c83..fe5bd6f9 100644
--- a/lib/coffee-script/lexer.js
+++ b/lib/coffee-script/lexer.js
@@ -813,7 +813,7 @@
 
   COFFEE_KEYWORDS = COFFEE_KEYWORDS.concat(COFFEE_ALIASES);
 
-  RESERVED = ['case', 'default', 'function', 'var', 'void', 'with', 'const', 'let', 'enum', 'export', 'import', 'native', '__hasProp', '__extends', '__slice', '__bind', '__indexOf', 'implements', 'interface', 'package', 'private', 'protected', 'public', 'static'];
+  RESERVED = ['case', 'default', 'function', 'var', 'void', 'with', 'const', 'let', 'enum', 'export', 'import', 'native', 'implements', 'interface', 'package', 'private', 'protected', 'public', 'static'];
 
   STRICT_PROSCRIBED = ['arguments', 'eval', 'yield*'];
 
diff --git a/lib/coffee-script/nodes.js b/lib/coffee-script/nodes.js
index 36e59ea9..f9eeb9a4 100644
--- a/lib/coffee-script/nodes.js
+++ b/lib/coffee-script/nodes.js
@@ -1,8 +1,8 @@
 // Generated by CoffeeScript 1.8.0
 (function() {
   var Access, Arr, Assign, Base, Block, Call, Class, Code, CodeFragment, Comment, Existence, Expansion, Extends, For, HEXNUM, IDENTIFIER, IDENTIFIER_STR, IS_REGEX, IS_STRING, If, In, Index, LEVEL_ACCESS, LEVEL_COND, LEVEL_LIST, LEVEL_OP, LEVEL_PAREN, LEVEL_TOP, Literal, METHOD_DEF, NEGATE, NO, NUMBER, Obj, Op, Param, Parens, RESERVED, Range, Return, SIMPLENUM, STRICT_PROSCRIBED, Scope, Slice, Splat, Switch, TAB, THIS, Throw, Try, UTILITIES, Value, While, YES, addLocationDataFn, compact, del, ends, extend, flatten, fragmentsToText, isLiteralArguments, isLiteralThis, last, locationDataToString, merge, multident, parseNum, some, starts, throwSyntaxError, unfoldSoak, utility, _ref, _ref1,
-    __hasProp = {}.hasOwnProperty,
     __extends = function(child, parent) { for (var key in parent) { if (__hasProp.call(parent, key)) child[key] = parent[key]; } function ctor() { this.constructor = child; } ctor.prototype = parent.prototype; child.prototype = new ctor(); child.__super__ = parent.prototype; return child; },
+    __hasProp = {}.hasOwnProperty,
     __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; },
     __slice = [].slice;
 
@@ -3145,9 +3145,13 @@
 
   utility = function(name) {
     var ref;
-    ref = "__" + name;
-    Scope.root.assign(ref, UTILITIES[name]());
-    return ref;
+    if (name in Scope.root.utilities) {
+      return Scope.root.utilities[name];
+    } else {
+      ref = Scope.root.freeVariable("_" + name);
+      Scope.root.assign(ref, UTILITIES[name]());
+      return Scope.root.utilities[name] = ref;
+    }
   };
 
   multident = function(code, tab) {
diff --git a/lib/coffee-script/scope.js b/lib/coffee-script/scope.js
index 75fc7eb4..2ffb641d 100644
--- a/lib/coffee-script/scope.js
+++ b/lib/coffee-script/scope.js
@@ -21,6 +21,7 @@
       ];
       this.positions = {};
       if (!this.parent) {
+        this.utilities = {};
         Scope.root = this;
       }
     }
diff --git a/src/lexer.coffee b/src/lexer.coffee
index 5a462e47..058fbcf7 100644
--- a/src/lexer.coffee
+++ b/src/lexer.coffee
@@ -718,9 +718,8 @@ COFFEE_KEYWORDS = COFFEE_KEYWORDS.concat COFFEE_ALIASES
 # to avoid having a JavaScript error at runtime.
 RESERVED = [
   'case', 'default', 'function', 'var', 'void', 'with', 'const', 'let', 'enum'
-  'export', 'import', 'native', '__hasProp', '__extends', '__slice', '__bind'
-  '__indexOf', 'implements', 'interface', 'package', 'private', 'protected'
-  'public', 'static'
+  'export', 'import', 'native', 'implements', 'interface', 'package', 'private'
+  'protected', 'public', 'static'
 ]
 
 STRICT_PROSCRIBED = ['arguments', 'eval', 'yield*']
diff --git a/src/nodes.coffee b/src/nodes.coffee
index 20ff9e90..d624b700 100644
--- a/src/nodes.coffee
+++ b/src/nodes.coffee
@@ -2260,9 +2260,12 @@ IS_REGEX = /^\//
 
 # Helper for ensuring that utility functions are assigned at the top level.
 utility = (name) ->
-  ref = "__#{name}"
-  Scope.root.assign ref, UTILITIES[name]()
-  ref
+  if name of Scope.root.utilities
+    Scope.root.utilities[name]
+  else
+    ref = Scope.root.freeVariable "_#{name}"
+    Scope.root.assign ref, UTILITIES[name]()
+    Scope.root.utilities[name] = ref
 
 multident = (code, tab) ->
   code = code.replace /\n/g, '$&' + tab
diff --git a/src/scope.litcoffee b/src/scope.litcoffee
index 132dc078..ab813ece 100644
--- a/src/scope.litcoffee
+++ b/src/scope.litcoffee
@@ -24,7 +24,9 @@ and therefore should be avoided when generating variables.
       constructor: (@parent, @expressions, @method, @referencedVars) ->
         @variables = [{name: 'arguments', type: 'arguments'}]
         @positions = {}
-        Scope.root = this unless @parent
+        unless @parent
+          @utilities = {}
+          Scope.root = this
 
 Adds a new variable or overrides an existing one.
 
diff --git a/test/assignment.coffee b/test/assignment.coffee
index 9753d3da..0ede9867 100644
--- a/test/assignment.coffee
+++ b/test/assignment.coffee
@@ -437,3 +437,23 @@ test "#1500: Assignment to variables similar to generated variables", ->
   eq 1, scope.a
 
   doesNotThrow -> CoffeeScript.compile '(@_slice...) ->'
+
+test "Assignment to variables similar to helper functions", ->
+  f = (__slice...) -> __slice
+  arrayEq [1, 2, 3], f 1, 2, 3
+  eq 'undefined', typeof __slice1
+
+  class A
+  class B extends A
+    __extends = 3
+    __hasProp = 4
+    value: 5
+    method: (__bind, __bind1) => [__bind, __bind1, __extends, __hasProp, @value]
+  {method} = new B
+  arrayEq [1, 2, 3, 4, 5], method 1, 2
+
+  __modulo = -1 %% 3
+  eq 2, __modulo
+
+  __indexOf = [1, 2, 3]
+  ok 2 in __indexOf