diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 50d17638371..489e44a9cd3 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -114,11 +114,10 @@ module ts {
         let globalIterableType: ObjectType;
 
         let anyArrayType: Type;
-        let globalTypedPropertyDescriptorType: ObjectType;
-        let globalClassDecoratorType: ObjectType;
-        let globalParameterDecoratorType: ObjectType;
-        let globalPropertyDecoratorType: ObjectType;
-        let globalMethodDecoratorType: ObjectType;
+        let getGlobalClassDecoratorType: () => ObjectType;
+        let getGlobalParameterDecoratorType: () => ObjectType;
+        let getGlobalPropertyDecoratorType: () => ObjectType;
+        let getGlobalMethodDecoratorType: () => ObjectType;
         
         let tupleTypes: Map<TupleType> = {};
         let unionTypes: Map<UnionType> = {};
@@ -8790,24 +8789,24 @@ module ts {
                 case SyntaxKind.ClassDeclaration:
                     let classSymbol = getSymbolOfNode(node.parent);
                     let classConstructorType = getTypeOfSymbol(classSymbol);
-                    let classDecoratorType = instantiateSingleCallFunctionType(globalClassDecoratorType, [classConstructorType]);
+                    let classDecoratorType = instantiateSingleCallFunctionType(getGlobalClassDecoratorType(), [classConstructorType]);
                     checkTypeAssignableTo(exprType, classDecoratorType, node);
                     break;
 
                 case SyntaxKind.PropertyDeclaration:
-                    checkTypeAssignableTo(exprType, globalPropertyDecoratorType, node);
+                    checkTypeAssignableTo(exprType, getGlobalPropertyDecoratorType(), node);
                     break;
 
                 case SyntaxKind.MethodDeclaration:
                 case SyntaxKind.GetAccessor:
                 case SyntaxKind.SetAccessor:
                     let methodType = getTypeOfNode(node.parent);
-                    let methodDecoratorType = instantiateSingleCallFunctionType(globalMethodDecoratorType, [methodType]);
+                    let methodDecoratorType = instantiateSingleCallFunctionType(getGlobalMethodDecoratorType(), [methodType]);
                     checkTypeAssignableTo(exprType, methodDecoratorType, node);
                     break;
 
                 case SyntaxKind.Parameter:
-                    checkTypeAssignableTo(exprType, globalParameterDecoratorType, node);
+                    checkTypeAssignableTo(exprType, getGlobalParameterDecoratorType(), node);
                     break;
             }
         }
@@ -11969,11 +11968,10 @@ module ts {
             globalNumberType = getGlobalType("Number");
             globalBooleanType = getGlobalType("Boolean");
             globalRegExpType = getGlobalType("RegExp");
-            globalTypedPropertyDescriptorType = getTypeOfGlobalSymbol(getGlobalTypeSymbol("TypedPropertyDescriptor"), 1);
-            globalClassDecoratorType = getGlobalType("ClassDecorator");
-            globalPropertyDecoratorType = getGlobalType("PropertyDecorator");
-            globalMethodDecoratorType = getGlobalType("MethodDecorator");
-            globalParameterDecoratorType = getGlobalType("ParameterDecorator");
+            getGlobalClassDecoratorType = memoize(() => getGlobalType("ClassDecorator"));
+            getGlobalPropertyDecoratorType = memoize(() => getGlobalType("PropertyDecorator"));
+            getGlobalMethodDecoratorType = memoize(() => getGlobalType("MethodDecorator"));
+            getGlobalParameterDecoratorType = memoize(() => getGlobalType("ParameterDecorator"));
 
             // If we're in ES6 mode, load the TemplateStringsArray.
             // Otherwise, default to 'unknown' for the purposes of type checking in LS scenarios.
diff --git a/src/compiler/core.ts b/src/compiler/core.ts
index 80840068332..6383108b0d6 100644
--- a/src/compiler/core.ts
+++ b/src/compiler/core.ts
@@ -281,6 +281,17 @@ module ts {
         return result;
     }
 
+    export function memoize<T>(callback: () => T): () => T {
+        let value: T;
+        return () => {
+            if (callback) {
+                value = callback();
+                callback = undefined;
+            }
+            return value;
+        };
+    }
+
     function formatStringFromArgs(text: string, args: { [index: number]: any; }, baseIndex?: number): string {
         baseIndex = baseIndex || 0;
 
diff --git a/tests/baselines/reference/noDefaultLib.errors.txt b/tests/baselines/reference/noDefaultLib.errors.txt
index c73f3e0b948..b8f42ba7c33 100644
--- a/tests/baselines/reference/noDefaultLib.errors.txt
+++ b/tests/baselines/reference/noDefaultLib.errors.txt
@@ -1,19 +1,9 @@
-error TS2318: Cannot find global type 'TypedPropertyDescriptor'.
-error TS2318: Cannot find global type 'PropertyDecorator'.
-error TS2318: Cannot find global type 'ParameterDecorator'.
-error TS2318: Cannot find global type 'MethodDecorator'.
 error TS2318: Cannot find global type 'IArguments'.
-error TS2318: Cannot find global type 'ClassDecorator'.
 error TS2318: Cannot find global type 'Boolean'.
 tests/cases/compiler/noDefaultLib.ts(4,11): error TS2317: Global type 'Array' must have 1 type parameter(s).
 
 
-!!! error TS2318: Cannot find global type 'TypedPropertyDescriptor'.
-!!! error TS2318: Cannot find global type 'PropertyDecorator'.
-!!! error TS2318: Cannot find global type 'ParameterDecorator'.
-!!! error TS2318: Cannot find global type 'MethodDecorator'.
 !!! error TS2318: Cannot find global type 'IArguments'.
-!!! error TS2318: Cannot find global type 'ClassDecorator'.
 !!! error TS2318: Cannot find global type 'Boolean'.
 ==== tests/cases/compiler/noDefaultLib.ts (1 errors) ====
     /// <reference no-default-lib="true"/>
diff --git a/tests/baselines/reference/parser509698.errors.txt b/tests/baselines/reference/parser509698.errors.txt
index 3dd70275e5c..85485dd6501 100644
--- a/tests/baselines/reference/parser509698.errors.txt
+++ b/tests/baselines/reference/parser509698.errors.txt
@@ -1,31 +1,21 @@
-error TS2318: Cannot find global type 'Number'.
-error TS2318: Cannot find global type 'TypedPropertyDescriptor'.
-error TS2318: Cannot find global type 'Object'.
-error TS2318: Cannot find global type 'Array'.
-error TS2318: Cannot find global type 'ClassDecorator'.
 error TS2318: Cannot find global type 'String'.
 error TS2318: Cannot find global type 'RegExp'.
-error TS2318: Cannot find global type 'PropertyDecorator'.
-error TS2318: Cannot find global type 'ParameterDecorator'.
+error TS2318: Cannot find global type 'Object'.
+error TS2318: Cannot find global type 'Number'.
+error TS2318: Cannot find global type 'IArguments'.
 error TS2318: Cannot find global type 'Function'.
 error TS2318: Cannot find global type 'Boolean'.
-error TS2318: Cannot find global type 'MethodDecorator'.
-error TS2318: Cannot find global type 'IArguments'.
+error TS2318: Cannot find global type 'Array'.
 
 
-!!! error TS2318: Cannot find global type 'Number'.
-!!! error TS2318: Cannot find global type 'TypedPropertyDescriptor'.
-!!! error TS2318: Cannot find global type 'Object'.
-!!! error TS2318: Cannot find global type 'Array'.
-!!! error TS2318: Cannot find global type 'ClassDecorator'.
 !!! error TS2318: Cannot find global type 'String'.
 !!! error TS2318: Cannot find global type 'RegExp'.
-!!! error TS2318: Cannot find global type 'PropertyDecorator'.
-!!! error TS2318: Cannot find global type 'ParameterDecorator'.
+!!! error TS2318: Cannot find global type 'Object'.
+!!! error TS2318: Cannot find global type 'Number'.
+!!! error TS2318: Cannot find global type 'IArguments'.
 !!! error TS2318: Cannot find global type 'Function'.
 !!! error TS2318: Cannot find global type 'Boolean'.
-!!! error TS2318: Cannot find global type 'MethodDecorator'.
-!!! error TS2318: Cannot find global type 'IArguments'.
+!!! error TS2318: Cannot find global type 'Array'.
 ==== tests/cases/conformance/parser/ecmascript5/RegressionTests/parser509698.ts (0 errors) ====
     /// <style requireSemi="on" />
     /// <reference no-default-lib="true"/>
diff --git a/tests/baselines/reference/project/noDefaultLib/amd/noDefaultLib.errors.txt b/tests/baselines/reference/project/noDefaultLib/amd/noDefaultLib.errors.txt
index 09264b901fc..e7db8a4da6a 100644
--- a/tests/baselines/reference/project/noDefaultLib/amd/noDefaultLib.errors.txt
+++ b/tests/baselines/reference/project/noDefaultLib/amd/noDefaultLib.errors.txt
@@ -1,32 +1,22 @@
-error TS2318: Cannot find global type 'Object'.
-error TS2318: Cannot find global type 'Array'.
-error TS2318: Cannot find global type 'ParameterDecorator'.
-error TS2318: Cannot find global type 'ClassDecorator'.
-error TS2318: Cannot find global type 'TypedPropertyDescriptor'.
 error TS2318: Cannot find global type 'String'.
 error TS2318: Cannot find global type 'RegExp'.
-error TS2318: Cannot find global type 'PropertyDecorator'.
+error TS2318: Cannot find global type 'Object'.
+error TS2318: Cannot find global type 'Number'.
+error TS2318: Cannot find global type 'IArguments'.
 error TS2318: Cannot find global type 'Function'.
 error TS2318: Cannot find global type 'Boolean'.
-error TS2318: Cannot find global type 'Number'.
-error TS2318: Cannot find global type 'MethodDecorator'.
-error TS2318: Cannot find global type 'IArguments'.
+error TS2318: Cannot find global type 'Array'.
 test.ts(3,8): error TS2304: Cannot find name 'Array'.
 
 
-!!! error TS2318: Cannot find global type 'Object'.
-!!! error TS2318: Cannot find global type 'Array'.
-!!! error TS2318: Cannot find global type 'ParameterDecorator'.
-!!! error TS2318: Cannot find global type 'ClassDecorator'.
-!!! error TS2318: Cannot find global type 'TypedPropertyDescriptor'.
 !!! error TS2318: Cannot find global type 'String'.
 !!! error TS2318: Cannot find global type 'RegExp'.
-!!! error TS2318: Cannot find global type 'PropertyDecorator'.
+!!! error TS2318: Cannot find global type 'Object'.
+!!! error TS2318: Cannot find global type 'Number'.
+!!! error TS2318: Cannot find global type 'IArguments'.
 !!! error TS2318: Cannot find global type 'Function'.
 !!! error TS2318: Cannot find global type 'Boolean'.
-!!! error TS2318: Cannot find global type 'Number'.
-!!! error TS2318: Cannot find global type 'MethodDecorator'.
-!!! error TS2318: Cannot find global type 'IArguments'.
+!!! error TS2318: Cannot find global type 'Array'.
 ==== test.ts (1 errors) ====
     /// <reference no-default-lib="true"/>
     
diff --git a/tests/baselines/reference/project/noDefaultLib/node/noDefaultLib.errors.txt b/tests/baselines/reference/project/noDefaultLib/node/noDefaultLib.errors.txt
index 09264b901fc..e7db8a4da6a 100644
--- a/tests/baselines/reference/project/noDefaultLib/node/noDefaultLib.errors.txt
+++ b/tests/baselines/reference/project/noDefaultLib/node/noDefaultLib.errors.txt
@@ -1,32 +1,22 @@
-error TS2318: Cannot find global type 'Object'.
-error TS2318: Cannot find global type 'Array'.
-error TS2318: Cannot find global type 'ParameterDecorator'.
-error TS2318: Cannot find global type 'ClassDecorator'.
-error TS2318: Cannot find global type 'TypedPropertyDescriptor'.
 error TS2318: Cannot find global type 'String'.
 error TS2318: Cannot find global type 'RegExp'.
-error TS2318: Cannot find global type 'PropertyDecorator'.
+error TS2318: Cannot find global type 'Object'.
+error TS2318: Cannot find global type 'Number'.
+error TS2318: Cannot find global type 'IArguments'.
 error TS2318: Cannot find global type 'Function'.
 error TS2318: Cannot find global type 'Boolean'.
-error TS2318: Cannot find global type 'Number'.
-error TS2318: Cannot find global type 'MethodDecorator'.
-error TS2318: Cannot find global type 'IArguments'.
+error TS2318: Cannot find global type 'Array'.
 test.ts(3,8): error TS2304: Cannot find name 'Array'.
 
 
-!!! error TS2318: Cannot find global type 'Object'.
-!!! error TS2318: Cannot find global type 'Array'.
-!!! error TS2318: Cannot find global type 'ParameterDecorator'.
-!!! error TS2318: Cannot find global type 'ClassDecorator'.
-!!! error TS2318: Cannot find global type 'TypedPropertyDescriptor'.
 !!! error TS2318: Cannot find global type 'String'.
 !!! error TS2318: Cannot find global type 'RegExp'.
-!!! error TS2318: Cannot find global type 'PropertyDecorator'.
+!!! error TS2318: Cannot find global type 'Object'.
+!!! error TS2318: Cannot find global type 'Number'.
+!!! error TS2318: Cannot find global type 'IArguments'.
 !!! error TS2318: Cannot find global type 'Function'.
 !!! error TS2318: Cannot find global type 'Boolean'.
-!!! error TS2318: Cannot find global type 'Number'.
-!!! error TS2318: Cannot find global type 'MethodDecorator'.
-!!! error TS2318: Cannot find global type 'IArguments'.
+!!! error TS2318: Cannot find global type 'Array'.
 ==== test.ts (1 errors) ====
     /// <reference no-default-lib="true"/>
     
diff --git a/tests/baselines/reference/typeCheckTypeArgument.errors.txt b/tests/baselines/reference/typeCheckTypeArgument.errors.txt
index e2d7d0532ff..2b2cb22e945 100644
--- a/tests/baselines/reference/typeCheckTypeArgument.errors.txt
+++ b/tests/baselines/reference/typeCheckTypeArgument.errors.txt
@@ -1,16 +1,11 @@
-error TS2318: Cannot find global type 'PropertyDecorator'.
-error TS2318: Cannot find global type 'Array'.
-error TS2318: Cannot find global type 'RegExp'.
-error TS2318: Cannot find global type 'ClassDecorator'.
 error TS2318: Cannot find global type 'String'.
+error TS2318: Cannot find global type 'Array'.
 error TS2318: Cannot find global type 'IArguments'.
-error TS2318: Cannot find global type 'TypedPropertyDescriptor'.
-error TS2318: Cannot find global type 'Number'.
 error TS2318: Cannot find global type 'Boolean'.
+error TS2318: Cannot find global type 'RegExp'.
 error TS2318: Cannot find global type 'Object'.
-error TS2318: Cannot find global type 'MethodDecorator'.
+error TS2318: Cannot find global type 'Number'.
 error TS2318: Cannot find global type 'Function'.
-error TS2318: Cannot find global type 'ParameterDecorator'.
 tests/cases/compiler/typeCheckTypeArgument.ts(3,19): error TS2304: Cannot find name 'UNKNOWN'.
 tests/cases/compiler/typeCheckTypeArgument.ts(5,26): error TS2304: Cannot find name 'UNKNOWN'.
 tests/cases/compiler/typeCheckTypeArgument.ts(7,21): error TS2304: Cannot find name 'UNKNOWN'.
@@ -19,19 +14,14 @@ tests/cases/compiler/typeCheckTypeArgument.ts(12,22): error TS2304: Cannot find
 tests/cases/compiler/typeCheckTypeArgument.ts(15,13): error TS2304: Cannot find name 'UNKNOWN'.
 
 
-!!! error TS2318: Cannot find global type 'PropertyDecorator'.
-!!! error TS2318: Cannot find global type 'Array'.
-!!! error TS2318: Cannot find global type 'RegExp'.
-!!! error TS2318: Cannot find global type 'ClassDecorator'.
 !!! error TS2318: Cannot find global type 'String'.
+!!! error TS2318: Cannot find global type 'Array'.
 !!! error TS2318: Cannot find global type 'IArguments'.
-!!! error TS2318: Cannot find global type 'TypedPropertyDescriptor'.
-!!! error TS2318: Cannot find global type 'Number'.
 !!! error TS2318: Cannot find global type 'Boolean'.
+!!! error TS2318: Cannot find global type 'RegExp'.
 !!! error TS2318: Cannot find global type 'Object'.
-!!! error TS2318: Cannot find global type 'MethodDecorator'.
+!!! error TS2318: Cannot find global type 'Number'.
 !!! error TS2318: Cannot find global type 'Function'.
-!!! error TS2318: Cannot find global type 'ParameterDecorator'.
 ==== tests/cases/compiler/typeCheckTypeArgument.ts (6 errors) ====
     /// <reference no-default-lib="true"/>