diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 274a7980ff1..7b78e19c5ef 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -16,6 +16,8 @@ module ts {
         var emptySymbols: SymbolTable = {};
 
         var compilerOptions = host.getCompilerOptions();
+        var languageVersion = compilerOptions.target || ScriptTarget.ES3;
+
         var emitResolver = createResolver();
 
         var checker: TypeChecker = {
@@ -6340,7 +6342,7 @@ module ts {
 
         function checkTaggedTemplateExpression(node: TaggedTemplateExpression): Type {
             // Grammar checking
-            if (!(compilerOptions.target >= ScriptTarget.ES6)) {
+            if (languageVersion < ScriptTarget.ES6) {
                 grammarErrorOnFirstToken(node.template, Diagnostics.Tagged_templates_are_only_available_when_targeting_ECMAScript_6_and_higher);
             }
 
@@ -10032,7 +10034,7 @@ module ts {
             globalRegExpType = getGlobalType("RegExp");
             // If we're in ES6 mode, load the TemplateStringsArray.
             // Otherwise, default to 'unknown' for the purposes of type checking in LS scenarios.
-            globalTemplateStringsArrayType = compilerOptions.target >= ScriptTarget.ES6
+            globalTemplateStringsArrayType = languageVersion >= ScriptTarget.ES6
                 ? getGlobalType("TemplateStringsArray")
                 : unknownType;
             anyArrayType = createArrayType(anyType);
@@ -10401,7 +10403,7 @@ module ts {
             return;
 
             var computedPropertyName = <ComputedPropertyName>node;
-            if (!(compilerOptions.target >= ScriptTarget.ES6)) {
+            if (languageVersion < ScriptTarget.ES6) {
                 grammarErrorOnNode(node, Diagnostics.Computed_property_names_are_only_available_when_targeting_ECMAScript_6_and_higher);
             }
             else if (computedPropertyName.expression.kind === SyntaxKind.BinaryExpression && (<BinaryExpression>computedPropertyName.expression).operator === SyntaxKind.CommaToken) {
@@ -10501,7 +10503,7 @@ module ts {
 
         function checkGrammarAccessor(accessor: MethodDeclaration): boolean {
             var kind = accessor.kind;
-            if (!(compilerOptions.target >= ScriptTarget.ES5)) {
+            if (languageVersion < ScriptTarget.ES5) {
                 return grammarErrorOnNode(accessor.name, Diagnostics.Accessors_are_only_available_when_targeting_ECMAScript_5_and_higher);
             }
             else if (isInAmbientContext(accessor)) {
@@ -10706,7 +10708,7 @@ module ts {
                 return grammarErrorAtPos(getSourceFileOfNode(declarationList), declarations.pos, declarations.end - declarations.pos, Diagnostics.Variable_declaration_list_cannot_be_empty);
             }
 
-            if (!(compilerOptions.target >= ScriptTarget.ES6)) {
+            if (languageVersion < ScriptTarget.ES6) {
                 if (isLet(declarationList)) {
                     return grammarErrorOnFirstToken(declarationList, Diagnostics.let_declarations_are_only_available_when_targeting_ECMAScript_6_and_higher);
                 }
@@ -10808,7 +10810,7 @@ module ts {
         function grammarErrorOnFirstToken(node: Node, message: DiagnosticMessage, arg0?: any, arg1?: any, arg2?: any): boolean {
             var sourceFile = getSourceFileOfNode(node);
             if (!hasParseDiagnostics(sourceFile)) {
-                var scanner = createScanner(compilerOptions.target, /*skipTrivia*/ true, sourceFile.text);
+                var scanner = createScanner(languageVersion, /*skipTrivia*/ true, sourceFile.text);
                 var start = scanToken(scanner, node.pos);
                 diagnostics.push(createFileDiagnostic(sourceFile, start, scanner.getTextPos() - start, message, arg0, arg1, arg2));
                 return true;
@@ -10950,7 +10952,7 @@ module ts {
                 if (node.parserContextFlags & ParserContextFlags.StrictMode) {
                     return grammarErrorOnNode(node, Diagnostics.Octal_literals_are_not_allowed_in_strict_mode);
                 }
-                else if (compilerOptions.target >= ScriptTarget.ES5) {
+                else if (languageVersion >= ScriptTarget.ES5) {
                     return grammarErrorOnNode(node, Diagnostics.Octal_literals_are_not_available_when_targeting_ECMAScript_5_and_higher);
                 }
             }
@@ -10959,7 +10961,7 @@ module ts {
         function grammarErrorAfterFirstToken(node: Node, message: DiagnosticMessage, arg0?: any, arg1?: any, arg2?: any): boolean {
             var sourceFile = getSourceFileOfNode(node);
             if (!hasParseDiagnostics(sourceFile)) {
-                var scanner = createScanner(compilerOptions.target, /*skipTrivia*/ true, sourceFile.text);
+                var scanner = createScanner(languageVersion, /*skipTrivia*/ true, sourceFile.text);
                 scanToken(scanner, node.pos);
                 diagnostics.push(createFileDiagnostic(sourceFile, scanner.getTextPos(), 0, message, arg0, arg1, arg2));
                 return true;
diff --git a/src/compiler/emitter.ts b/src/compiler/emitter.ts
index abef385c76c..25cb7a8b2ee 100644
--- a/src/compiler/emitter.ts
+++ b/src/compiler/emitter.ts
@@ -339,6 +339,7 @@ module ts {
     function emitDeclarations(host: EmitHost, resolver: EmitResolver, diagnostics: Diagnostic[], jsFilePath: string, root?: SourceFile): DeclarationEmit {
         var newLine = host.getNewLine();
         var compilerOptions = host.getCompilerOptions();
+        var languageVersion = compilerOptions.target || ScriptTarget.ES3;
 
         var write: (s: string) => void;
         var writeLine: () => void;
@@ -1473,6 +1474,7 @@ module ts {
     export function emitFiles(resolver: EmitResolver, host: EmitHost, targetSourceFile?: SourceFile): EmitResult {
         // var program = resolver.getProgram();
         var compilerOptions = host.getCompilerOptions();
+        var languageVersion = compilerOptions.target || ScriptTarget.ES3;
         var sourceMapDataList: SourceMapData[] = compilerOptions.sourceMap ? [] : undefined;
         var diagnostics: Diagnostic[] = [];
         var newLine = host.getNewLine();
@@ -2021,14 +2023,14 @@ module ts {
             }
 
             function emitLiteral(node: LiteralExpression) {
-                var text = !(compilerOptions.target >= ScriptTarget.ES6) && isTemplateLiteralKind(node.kind) ? getTemplateLiteralAsStringLiteral(node) :
+                var text = languageVersion < ScriptTarget.ES6 && isTemplateLiteralKind(node.kind) ? getTemplateLiteralAsStringLiteral(node) :
                     node.parent ? getSourceTextOfNodeFromSourceFile(currentSourceFile, node) :
                     node.text;
                 if (compilerOptions.sourceMap && (node.kind === SyntaxKind.StringLiteral || isTemplateLiteralKind(node.kind))) {
                     writer.writeLiteral(text);
                 }
                 // For version below ES6, emit binary integer literal and octal integer literal in canonical form
-                else if (!(compilerOptions.target >= ScriptTarget.ES6) && node.kind === SyntaxKind.NumericLiteral && isBinaryOrOctalIntegerLiteral(text)) {
+                else if (languageVersion < ScriptTarget.ES6 && node.kind === SyntaxKind.NumericLiteral && isBinaryOrOctalIntegerLiteral(text)) {
                     write(node.text);
                 }
                 else {
@@ -2043,7 +2045,7 @@ module ts {
             function emitTemplateExpression(node: TemplateExpression): void {
                 // In ES6 mode and above, we can simply emit each portion of a template in order, but in
                 // ES3 & ES5 we must convert the template expression into a series of string concatenations.
-                if (compilerOptions.target >= ScriptTarget.ES6) {
+                if (languageVersion >= ScriptTarget.ES6) {
                     forEachChild(node, emit);
                     return;
                 }
@@ -2150,7 +2152,7 @@ module ts {
                     // 
                     // TODO (drosen): Note that we need to account for the upcoming 'yield' and
                     //                spread ('...') unary operators that are anticipated for ES6.
-                    Debug.assert(!(compilerOptions.target >= ScriptTarget.ES6));
+                    Debug.assert(languageVersion < ScriptTarget.ES6);
                     switch (expression.kind) {
                         case SyntaxKind.BinaryExpression:
                             switch ((<BinaryExpression>expression).operator) {
@@ -2335,7 +2337,7 @@ module ts {
                     write("[]");
                     return;
                 }
-                if (compilerOptions.target >= ScriptTarget.ES6) {
+                if (languageVersion >= ScriptTarget.ES6) {
                     write("[");
                     emitList(elements, 0, elements.length, /*multiLine*/(node.flags & NodeFlags.MultiLine) !== 0,
                         /*trailingComma*/ elements.hasTrailingComma);
@@ -2385,7 +2387,7 @@ module ts {
                         write(" ");
                     }
                     emitList(properties, 0, properties.length, /*multiLine*/ multiLine,
-                        /*trailingComma*/ properties.hasTrailingComma && compilerOptions.target >= ScriptTarget.ES5);
+                        /*trailingComma*/ properties.hasTrailingComma && languageVersion >= ScriptTarget.ES5);
                     if (!multiLine) {
                         write(" ");
                     }
@@ -2405,7 +2407,7 @@ module ts {
                 }
                 emitLeadingComments(node);
                 emit(node.name);
-                if (!(compilerOptions.target >= ScriptTarget.ES6)) {
+                if (languageVersion < ScriptTarget.ES6) {
                     write(": function ");
                 }
                 emitSignatureAndBody(node);
@@ -2431,7 +2433,7 @@ module ts {
                 //      export var obj = { y };
                 //  }
                 //  The short-hand property in obj need to emit as such ... = { y : m.y } regardless of the TargetScript version
-                if (!(compilerOptions.target >= ScriptTarget.ES6) || resolver.getExpressionNamePrefix(node.name)) {
+                if (languageVersion < ScriptTarget.ES6 || resolver.getExpressionNamePrefix(node.name)) {
                     // Emit identifier as an identifier
                     write(": ");
                     // Even though this is stored as identifier treat it as an expression
@@ -2513,7 +2515,7 @@ module ts {
             }
 
             function emitTaggedTemplateExpression(node: TaggedTemplateExpression): void {
-                Debug.assert(compilerOptions.target >= ScriptTarget.ES6, "Trying to emit a tagged template in pre-ES6 mode.");
+                Debug.assert(languageVersion >= ScriptTarget.ES6, "Trying to emit a tagged template in pre-ES6 mode.");
                 emit(node.tag);
                 write(" ");
                 emit(node.template);
@@ -2605,7 +2607,7 @@ module ts {
 
 
             function emitBinaryExpression(node: BinaryExpression) {
-                if (!(compilerOptions.target >= ScriptTarget.ES6) && node.operator === SyntaxKind.EqualsToken &&
+                if (languageVersion < ScriptTarget.ES6 && node.operator === SyntaxKind.EqualsToken &&
                     (node.left.kind === SyntaxKind.ObjectLiteralExpression || node.left.kind === SyntaxKind.ArrayLiteralExpression)) {
                     emitDestructuring(node);
                 }
@@ -3101,7 +3103,7 @@ module ts {
             function emitVariableDeclaration(node: VariableDeclaration) {
                 emitLeadingComments(node);
                 if (isBindingPattern(node.name)) {
-                    if (!(compilerOptions.target >= ScriptTarget.ES6)) {
+                    if (languageVersion < ScriptTarget.ES6) {
                         emitDestructuring(node);
                     }
                     else {
@@ -3136,7 +3138,7 @@ module ts {
 
             function emitParameter(node: ParameterDeclaration) {
                 emitLeadingComments(node);
-                if (!(compilerOptions.target >= ScriptTarget.ES6)) {
+                if (languageVersion < ScriptTarget.ES6) {
                     if (isBindingPattern(node.name)) {
                         var name = createTempVariable(node);
                         if (!tempParameters) {
@@ -3160,7 +3162,7 @@ module ts {
             }
 
             function emitDefaultValueAssignments(node: FunctionLikeDeclaration) {
-                if (!(compilerOptions.target >= ScriptTarget.ES6)) {
+                if (languageVersion < ScriptTarget.ES6) {
                     var tempIndex = 0;
                     forEach(node.parameters, p => {
                         if (isBindingPattern(p.name)) {
@@ -3190,7 +3192,7 @@ module ts {
             }
 
             function emitRestParameter(node: FunctionLikeDeclaration) {
-                if (!(compilerOptions.target >= ScriptTarget.ES6) && hasRestParameters(node)) {
+                if (languageVersion < ScriptTarget.ES6 && hasRestParameters(node)) {
                     var restIndex = node.parameters.length - 1;
                     var restParam = node.parameters[restIndex];
                     var tempName = createTempVariable(node, /*forLoopVariable*/ true).text;
@@ -3269,7 +3271,7 @@ module ts {
                 write("(");
                 if (node) {
                     var parameters = node.parameters;
-                    var omitCount = !(compilerOptions.target >= ScriptTarget.ES6) && hasRestParameters(node) ? 1 : 0;
+                    var omitCount = languageVersion < ScriptTarget.ES6 && hasRestParameters(node) ? 1 : 0;
                     emitList(parameters, 0, parameters.length - omitCount, /*multiLine*/ false, /*trailingComma*/ false);
                 }
                 write(")");