diff --git a/src/compiler/binder.ts b/src/compiler/binder.ts
index fe3009da3a..cdc868f408 100644
--- a/src/compiler/binder.ts
+++ b/src/compiler/binder.ts
@@ -18,7 +18,7 @@ module ts {
             return ModuleInstanceState.NonInstantiated;
         }
         // 2. const enum declarations don't make module instantiated
-        else if (node.kind === SyntaxKind.EnumDeclaration && isConstEnumDeclaration(<EnumDeclaration>node)) {
+        else if (isConstEnumDeclaration(node)) {
             return ModuleInstanceState.ConstEnumOnly;
         }
         // 3. non - exported import declarations
@@ -402,7 +402,7 @@ module ts {
                     bindDeclaration(<Declaration>node, SymbolFlags.TypeAlias, SymbolFlags.TypeAliasExcludes, /*isBlockScopeContainer*/ false);
                     break;
                 case SyntaxKind.EnumDeclaration:
-                    if (isConstEnumDeclaration(<EnumDeclaration>node)) {
+                    if (isConst(node)) {
                         bindDeclaration(<Declaration>node, SymbolFlags.ConstEnum, SymbolFlags.ConstEnumExcludes, /*isBlockScopeContainer*/ false);
                     }
                     else {
diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 5a990d4e9d..ec075dbce4 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -7940,7 +7940,7 @@ module ts {
                 var enumType = getDeclaredTypeOfSymbol(enumSymbol);
                 var autoValue = 0;
                 var ambient = isInAmbientContext(node);
-                var enumIsConst = isConstEnumDeclaration(node);
+                var enumIsConst = isConst(node);
 
                 forEach(node.members, member => {
                     // TODO(jfreeman): Check that it is not a computed name
@@ -8111,10 +8111,10 @@ module ts {
             var firstDeclaration = getDeclarationOfKind(enumSymbol, node.kind);
             if (node === firstDeclaration) {
                 if (enumSymbol.declarations.length > 1) {
-                    var enumIsConst = isConstEnumDeclaration(node);
+                    var enumIsConst = isConst(node);
                     // check that const is placed\omitted on all enum declarations
                     forEach(enumSymbol.declarations, decl => {
-                        if (isConstEnumDeclaration(<EnumDeclaration>decl) !== enumIsConst) {
+                        if (isConstEnumDeclaration(decl) !== enumIsConst) {
                             error(decl.name, Diagnostics.Enum_declarations_must_all_be_const_or_non_const);
                         }
                     });
diff --git a/src/compiler/emitter.ts b/src/compiler/emitter.ts
index f61d4403ee..937b64979e 100644
--- a/src/compiler/emitter.ts
+++ b/src/compiler/emitter.ts
@@ -1271,10 +1271,10 @@ module ts {
                 write(" ");
                 endPos = emitToken(SyntaxKind.OpenParenToken, endPos);
                 if (node.declarations) {
-                    if (node.declarations[0] && node.declarations[0].flags & NodeFlags.Let) {
+                    if (node.declarations[0] && isLet(node.declarations[0])) {
                         emitToken(SyntaxKind.LetKeyword, endPos);
                     }
-                    else if (node.declarations[0] && node.declarations[0].flags & NodeFlags.Const) {
+                    else if (node.declarations[0] && isConst(node.declarations[0])) {
                         emitToken(SyntaxKind.ConstKeyword, endPos);
                     }
                     else {
@@ -1299,7 +1299,7 @@ module ts {
                 write(" ");
                 endPos = emitToken(SyntaxKind.OpenParenToken, endPos);
                 if (node.declaration) {
-                    if (node.declaration.flags & NodeFlags.Let) {
+                    if (isLet(node.declaration)) {
                         emitToken(SyntaxKind.LetKeyword, endPos);
                     }
                     else {
@@ -1445,10 +1445,10 @@ module ts {
             function emitVariableStatement(node: VariableStatement) {
                 emitLeadingComments(node);
                 if (!(node.flags & NodeFlags.Export)) {
-                    if (node.flags & NodeFlags.Let) {
+                    if (isLet(node)) {
                         write("let ");
                     }
-                    else if (node.flags & NodeFlags.Const) {
+                    else if (isConst(node)) {
                         write("const ");
                     }
                     else {
@@ -1901,7 +1901,7 @@ module ts {
 
             function emitEnumDeclaration(node: EnumDeclaration) {
                 // const enums are completely erased during compilation.
-                var isConstEnum = isConstEnumDeclaration(node);
+                var isConstEnum = isConst(node);
                 if (isConstEnum && !compilerOptions.preserveConstEnums) {
                     return;
                 }
@@ -2754,7 +2754,7 @@ module ts {
                 if (resolver.isDeclarationVisible(node)) {
                     emitJsDocComments(node);
                     emitDeclarationFlags(node);
-                    if (isConstEnumDeclaration(node)) {
+                    if (isConst(node)) {
                         write("const ")
                     }
                     write("enum ");
@@ -3041,10 +3041,10 @@ module ts {
                 if (hasDeclarationWithEmit) {
                     emitJsDocComments(node);
                     emitDeclarationFlags(node);
-                    if (node.flags & NodeFlags.Let) {
+                    if (isLet(node)) {
                         write("let ");
                     }
-                    else if (node.flags & NodeFlags.Const) {
+                    else if (isConst(node)) {
                         write("const ");
                     }
                     else {
diff --git a/src/compiler/parser.ts b/src/compiler/parser.ts
index 4849cb8c89..01a5f05229 100644
--- a/src/compiler/parser.ts
+++ b/src/compiler/parser.ts
@@ -116,8 +116,16 @@ module ts {
         return (file.flags & NodeFlags.DeclarationFile) !== 0;
     }
 
-    export function isConstEnumDeclaration(node: EnumDeclaration): boolean {
-        return (node.flags & NodeFlags.Const) !== 0;
+    export function isConstEnumDeclaration(node: Declaration): boolean {
+        return node.kind === SyntaxKind.EnumDeclaration && !!(node.flags & NodeFlags.Const);
+    }
+
+    export function isConst(node: Declaration): boolean {
+        return !!(node.flags & NodeFlags.Const);
+    }
+
+    export function isLet(node: Declaration): boolean {
+        return !!(node.flags & NodeFlags.Let);
     }
 
     export function isPrologueDirective(node: Node): boolean {
@@ -3480,18 +3488,18 @@ module ts {
                 grammarErrorOnNode(node, Diagnostics.Variable_declaration_list_cannot_be_empty);
             }
             if (languageVersion < ScriptTarget.ES6) {
-                if (node.flags & NodeFlags.Let) {
+                if (isLet(node)) {
                     grammarErrorOnNode(node, Diagnostics.let_declarations_are_only_available_when_targeting_ECMAScript_6_and_higher);
                 }
-                else if (node.flags & NodeFlags.Const) {
+                else if (isConst(node)) {
                     grammarErrorOnNode(node, Diagnostics.const_declarations_are_only_available_when_targeting_ECMAScript_6_and_higher);
                 }
             }
             else if (!allowLetAndConstDeclarations) {
-                if (node.flags & NodeFlags.Let) {
+                if (isLet(node)) {
                     grammarErrorOnNode(node, Diagnostics.let_declarations_can_only_be_declared_inside_a_block);
                 }
-                else if (node.flags & NodeFlags.Const) {
+                else if (isConst(node)) {
                     grammarErrorOnNode(node, Diagnostics.const_declarations_can_only_be_declared_inside_a_block);
                 }
             }
diff --git a/src/services/navigationBar.ts b/src/services/navigationBar.ts
index b8106fc18d..fd3ea13ce6 100644
--- a/src/services/navigationBar.ts
+++ b/src/services/navigationBar.ts
@@ -235,7 +235,7 @@ module ts.NavigationBar {
                     return createItem(node, getTextOfNode((<FunctionLikeDeclaration>node).name), ts.ScriptElementKind.functionElement);
 
                 case SyntaxKind.VariableDeclaration:
-                    if (node.flags & NodeFlags.Const) {
+                    if (isConst(node)) {
                         return createItem(node, getTextOfNode((<VariableDeclaration>node).name), ts.ScriptElementKind.constantElement);
                     }
                     else if (node.flags & NodeFlags.Let) {
diff --git a/src/services/services.ts b/src/services/services.ts
index 8d48f0bfe1..bf9bdb0ee7 100644
--- a/src/services/services.ts
+++ b/src/services/services.ts
@@ -2859,7 +2859,7 @@ module ts {
                 if (isFirstDeclarationOfSymbolParameter(symbol)) {
                     return ScriptElementKind.parameterElement;
                 }
-                else if (symbol.valueDeclaration && symbol.valueDeclaration.flags & NodeFlags.Const) {
+                else if (symbol.valueDeclaration && isConst(symbol.valueDeclaration)) {
                     return ScriptElementKind.constantElement;
                 }
                 else if (forEach(symbol.declarations, declaration => declaration.flags & NodeFlags.Let)) {
@@ -2920,11 +2920,11 @@ module ts {
                 case SyntaxKind.InterfaceDeclaration: return ScriptElementKind.interfaceElement;
                 case SyntaxKind.TypeAliasDeclaration: return ScriptElementKind.typeElement;
                 case SyntaxKind.EnumDeclaration: return ScriptElementKind.enumElement;
-                case SyntaxKind.VariableDeclaration: return node.flags & NodeFlags.Const ?
-                    ScriptElementKind.constantElement :
-                    node.flags & NodeFlags.Let ?
-                    ScriptElementKind.letElement :
-                    ScriptElementKind.variableElement;
+                case SyntaxKind.VariableDeclaration: return isConst(node)
+                    ? ScriptElementKind.constantElement
+                    : node.flags & NodeFlags.Let
+                        ? ScriptElementKind.letElement
+                        : ScriptElementKind.variableElement;
                 case SyntaxKind.FunctionDeclaration: return ScriptElementKind.functionElement;
                 case SyntaxKind.GetAccessor: return ScriptElementKind.memberGetAccessorElement;
                 case SyntaxKind.SetAccessor: return ScriptElementKind.memberSetAccessorElement;
@@ -3099,8 +3099,7 @@ module ts {
             }
             if (symbolFlags & SymbolFlags.Enum) {
                 addNewLineIfDisplayPartsExist();
-                if (forEach(symbol.declarations, declaration =>
-                    declaration.kind === SyntaxKind.EnumDeclaration && isConstEnumDeclaration(<EnumDeclaration>declaration))) {
+                if (forEach(symbol.declarations, declaration => isConstEnumDeclaration(declaration))) {
                     displayParts.push(keywordPart(SyntaxKind.ConstKeyword));
                     displayParts.push(spacePart());
                 }