diff --git a/src/Core/Compiler/Generator/ExpressionGenerator.cs b/src/Core/Compiler/Generator/ExpressionGenerator.cs
index e6c9d44a6..f05d70f36 100644
--- a/src/Core/Compiler/Generator/ExpressionGenerator.cs
+++ b/src/Core/Compiler/Generator/ExpressionGenerator.cs
@@ -43,11 +43,10 @@ private static void GenerateBinaryExpression(ScriptGenerator generator, MemberSy
                     Debug.Assert(propExpression.Type == ExpressionType.PropertySet);
 
                     if (propExpression.ObjectReference is BaseExpression) {
-                        writer.Write("ss.base(");
-                        writer.Write(generator.CurrentImplementation.ThisIdentifier);
-                        writer.Write(", 'set_");
+                        writer.Write(((BaseExpression)propExpression.ObjectReference).EvaluatedType.FullGeneratedName);
+                        writer.Write(".prototype.set_");
                         writer.Write(propExpression.Property.GeneratedName);
-                        writer.Write("').call(");
+                        writer.Write(".call(");
                         writer.Write(generator.CurrentImplementation.ThisIdentifier);
                         writer.Write(", ");
                         GenerateExpression(generator, symbol, expression.RightOperand);
@@ -71,11 +70,10 @@ private static void GenerateBinaryExpression(ScriptGenerator generator, MemberSy
                     Debug.Assert(indexExpression.Type == ExpressionType.Indexer);
 
                     if (indexExpression.ObjectReference is BaseExpression) {
-                        writer.Write("ss.base(");
-                        writer.Write(generator.CurrentImplementation.ThisIdentifier);
-                        writer.Write(", 'set_");
+                        writer.Write(((BaseExpression)indexExpression.ObjectReference).EvaluatedType.FullGeneratedName);
+                        writer.Write(".prototype.set_");
                         writer.Write(indexExpression.Indexer.GeneratedName);
-                        writer.Write("').call(");
+                        writer.Write(".call(");
                         writer.Write(generator.CurrentImplementation.ThisIdentifier);
                         writer.Write(", ");
                         GenerateExpressionList(generator, symbol, indexExpression.Indices);
@@ -478,11 +476,10 @@ private static void GenerateIndexerExpression(ScriptGenerator generator, MemberS
                 writer.Write("]");
             }
             else if (expression.ObjectReference is BaseExpression) {
-                writer.Write("ss.base(");
-                writer.Write(generator.CurrentImplementation.ThisIdentifier);
-                writer.Write(", 'get_");
+                writer.Write(((BaseExpression)expression.ObjectReference).EvaluatedType.FullGeneratedName);
+                writer.Write(".prototype.get_");
                 writer.Write(expression.Indexer.GeneratedName);
-                writer.Write("').call(");
+                writer.Write(".call(");
                 writer.Write(generator.CurrentImplementation.ThisIdentifier);
                 writer.Write(", ");
                 GenerateExpressionList(generator, symbol, expression.Indices);
@@ -707,11 +704,10 @@ private static void GenerateMethodExpression(ScriptGenerator generator, MemberSy
             if (expression.ObjectReference is BaseExpression) {
                 Debug.Assert(expression.Method.IsExtension == false);
 
-                writer.Write("ss.base(");
-                writer.Write(generator.CurrentImplementation.ThisIdentifier);
-                writer.Write(", '");
+                writer.Write(((BaseExpression)expression.ObjectReference).EvaluatedType.FullGeneratedName);
+                writer.Write(".prototype.");
                 writer.Write(expression.Method.GeneratedName);
-                writer.Write("').call(");
+                writer.Write(".call(");
                 writer.Write(generator.CurrentImplementation.ThisIdentifier);
                 if ((expression.Parameters != null) && (expression.Parameters.Count != 0)) {
                     writer.Write(", ");
diff --git a/src/Core/Scripts/Runtime.js b/src/Core/Scripts/Runtime.js
index 4fa0d4d37..beba55767 100644
--- a/src/Core/Scripts/Runtime.js
+++ b/src/Core/Scripts/Runtime.js
@@ -95,7 +95,6 @@
       safeCast: safeCast,
       canAssign: canAssign,
       instanceOf: instanceOf,
-      base: base,
 
       culture: {
         neutral: neutralCulture,
diff --git a/src/Core/Scripts/Runtime/TypeSystem.js b/src/Core/Scripts/Runtime/TypeSystem.js
index c478b92ff..5bf79bcfc 100644
--- a/src/Core/Scripts/Runtime/TypeSystem.js
+++ b/src/Core/Scripts/Runtime/TypeSystem.js
@@ -153,12 +153,6 @@ function safeCast(instance, type) {
   return instanceOf(type, instance) ? instance : null;
 }
 
-function base(instanceOrType, method) {
-  var baseType = instanceOrType.constructor.$base || instanceOrType.$base;
-  var m = baseType.prototype[method];
-  return m !== instanceOrType[method] ? m : base(baseType, method);
-}
-
 function module(name, implementation, exports) {
   var registry = _modules[name] = { $name: name };
 
diff --git a/tests/TestCases/Basic/Minimization/Baseline.txt b/tests/TestCases/Basic/Minimization/Baseline.txt
index cf463a71c..daf9da6f6 100644
--- a/tests/TestCases/Basic/Minimization/Baseline.txt
+++ b/tests/TestCases/Basic/Minimization/Baseline.txt
@@ -173,7 +173,7 @@ define('test', ['ss', 'lib'], function(ss, lib) {
     },
     $0: function() {
       this.$2();
-      ss.base(this, '$0').call(this);
+      Bar2.prototype.$0.call(this);
       var d = MyData('a', 'b');
       d.$0 = d.$1;
     },
@@ -273,7 +273,7 @@ define('test', ['ss', 'lib'], function(ss, lib) {
     },
     dispose: function() {
       this.c$0 = 0;
-      ss.base(this, 'dispose').call(this);
+      lib.Behavior.prototype.dispose.call(this);
     },
     c$6: function() {
     },
diff --git a/tests/TestCases/Expression/Base/Baseline.txt b/tests/TestCases/Expression/Base/Baseline.txt
index 60080165b..8c8ee0fd1 100644
--- a/tests/TestCases/Expression/Base/Baseline.txt
+++ b/tests/TestCases/Expression/Base/Baseline.txt
@@ -24,10 +24,10 @@ define('test', ['ss'], function(ss) {
   }
   var Bar$ = {
     sum: function() {
-      return ss.base(this, 'sum').call(this, 1) + 1;
+      return Foo.prototype.sum.call(this, 1) + 1;
     },
     toString: function() {
-      return ss.base(this, 'toString').call(this) + ' -> Bar';
+      return Foo.prototype.toString.call(this) + ' -> Bar';
     }
   };
 
diff --git a/tests/TestCases/Expression/Members/Baseline.txt b/tests/TestCases/Expression/Members/Baseline.txt
index f5b380079..322c8d28e 100644
--- a/tests/TestCases/Expression/Members/Baseline.txt
+++ b/tests/TestCases/Expression/Members/Baseline.txt
@@ -70,7 +70,7 @@ define('test', ['ss'], function(ss) {
       n = App.prototype.get_XYZ.call(this);
       this.set_XYZ(n);
       this.set_XYZ(n);
-      ss.base(this, 'set_XYZ').call(this, n);
+      App.prototype.set_XYZ.call(this, n);
       this._value2 = n;
       this._value2 = n;
       this._value2 = n;
diff --git a/tests/TestCases/Member/Indexers/Baseline.txt b/tests/TestCases/Member/Indexers/Baseline.txt
index a4db55dd7..3c2065171 100644
--- a/tests/TestCases/Member/Indexers/Baseline.txt
+++ b/tests/TestCases/Member/Indexers/Baseline.txt
@@ -133,15 +133,15 @@ define('test', ['ss'], function(ss) {
     VirtualIndexer.call(this);
     var i = this.get_item('name');
     this.set_item('name', i + 1);
-    var j = ss.base(this, 'get_item').call(this, 'name');
-    ss.base(this, 'set_item').call(this, 'name', 43);
+    var j = VirtualIndexer.prototype.get_item.call(this, 'name');
+    VirtualIndexer.prototype.set_item.call(this, 'name', 43);
   }
   var OverriddenIndexer$ = {
     get_item: function(name) {
-      return ss.base(this, 'get_item').call(this, name) + 1;
+      return VirtualIndexer.prototype.get_item.call(this, name) + 1;
     },
     set_item: function(name, value) {
-      ss.base(this, 'set_item').call(this, name, value - 1);
+      VirtualIndexer.prototype.set_item.call(this, name, value - 1);
       return value;
     }
   };
diff --git a/tests/TestCases/Type/Partials/Baseline.txt b/tests/TestCases/Type/Partials/Baseline.txt
index 968a6db33..11d256e6c 100644
--- a/tests/TestCases/Type/Partials/Baseline.txt
+++ b/tests/TestCases/Type/Partials/Baseline.txt
@@ -112,7 +112,7 @@ define('test', ['ss'], function(ss) {
       var e1 = document.getElementById(this.bar);
       var e2 = document.getElementById(this.name);
       var e3 = document.getElementById(this.bar);
-      var s = this.testMethod() + ss.base(this, 'testMethod').call(this);
+      var s = this.testMethod() + MergedMembersClass.prototype.testMethod.call(this);
     },
     get_item: function(s) {
       return s;