diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index faac9105e29..1ab1a09f71e 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -11,11 +11,6 @@ module ts {
     var nextNodeId = 1;
     var nextMergeId = 1;
 
-    // unknownSymbol can survive across different type checking sessions (e.g. in the language service)
-    // We use referential comparison to know if a symbol is the unknown symbol; creating a new symbol
-    // every time would defy that purpose. So we need to have a single object to represent the "unknown" symbol.
-    var unknownSymbol: Symbol;
-
     export function createTypeChecker(program: Program): TypeChecker {
 
         var Symbol = objectAllocator.getSymbolConstructor();
@@ -29,12 +24,9 @@ module ts {
 
         var undefinedSymbol = createSymbol(SymbolFlags.Property | SymbolFlags.Transient, "undefined");
         var argumentsSymbol = createSymbol(SymbolFlags.Property | SymbolFlags.Transient, "arguments");
+        var unknownSymbol = createSymbol(SymbolFlags.Property | SymbolFlags.Transient, "unknown");
         var resolvingSymbol = createSymbol(SymbolFlags.Transient, "__resolving__");
 
-        if (!unknownSymbol) {
-            unknownSymbol = createSymbol(SymbolFlags.Property | SymbolFlags.Transient, "unknown");
-        }
-
         var anyType = createIntrinsicType(TypeFlags.Any, "any");
         var stringType = createIntrinsicType(TypeFlags.String, "string");
         var numberType = createIntrinsicType(TypeFlags.Number, "number");