diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 8fe31a0c5ce..737393486b2 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -8182,8 +8182,26 @@ module ts {
         }
 
         function checkSwitchStatement(node: SwitchStatement) {
+            // Grammar checking
+            var firstDefaultClause: CaseOrDefaultClause;
+            var hasDuplicateDefaultClause = false;
+
             var expressionType = checkExpression(node.expression);
             forEach(node.clauses, clause => {
+                // Grammar check for duplicate default clauses, skip if we already report duplicate default clause
+                if (clause.kind === SyntaxKind.DefaultClause && !hasDuplicateDefaultClause) {
+                    if (firstDefaultClause === undefined) {
+                        firstDefaultClause = clause;
+                    }
+                    else {
+                        var sourceFile = getSourceFileOfNode(node);
+                        var start = skipTrivia(sourceFile.text, clause.pos);
+                        var end = clause.statements.length > 0 ? clause.statements[0].pos : clause.end;
+                        grammarErrorAtPos(sourceFile, start, end - start, Diagnostics.A_default_clause_cannot_appear_more_than_once_in_a_switch_statement);
+                        hasDuplicateDefaultClause = true;
+                    }
+                }
+
                 if (fullTypeCheck && clause.kind === SyntaxKind.CaseClause) {
                     var caseClause = <CaseClause>clause;
                     // TypeScript 1.0 spec (April 2014):5.9
diff --git a/src/compiler/diagnosticInformationMap.generated.ts b/src/compiler/diagnosticInformationMap.generated.ts
index c9bf3883200..1a25fdcffe9 100644
--- a/src/compiler/diagnosticInformationMap.generated.ts
+++ b/src/compiler/diagnosticInformationMap.generated.ts
@@ -76,7 +76,7 @@ module ts {
         Type_expected: { code: 1110, category: DiagnosticCategory.Error, key: "Type expected.", isEarly: true },
         A_constructor_implementation_cannot_be_declared_in_an_ambient_context: { code: 1111, category: DiagnosticCategory.Error, key: "A constructor implementation cannot be declared in an ambient context.", isEarly: true },
         A_class_member_cannot_be_declared_optional: { code: 1112, category: DiagnosticCategory.Error, key: "A class member cannot be declared optional.", isEarly: true },
-        A_default_clause_cannot_appear_more_than_once_in_a_switch_statement: { code: 1113, category: DiagnosticCategory.Error, key: "A 'default' clause cannot appear more than once in a 'switch' statement." },
+        A_default_clause_cannot_appear_more_than_once_in_a_switch_statement: { code: 1113, category: DiagnosticCategory.Error, key: "A 'default' clause cannot appear more than once in a 'switch' statement.", isEarly: true },
         Duplicate_label_0: { code: 1114, category: DiagnosticCategory.Error, key: "Duplicate label '{0}'", isEarly: true },
         A_continue_statement_can_only_jump_to_a_label_of_an_enclosing_iteration_statement: { code: 1115, category: DiagnosticCategory.Error, key: "A 'continue' statement can only jump to a label of an enclosing iteration statement.", isEarly: true },
         A_break_statement_can_only_jump_to_a_label_of_an_enclosing_statement: { code: 1116, category: DiagnosticCategory.Error, key: "A 'break' statement can only jump to a label of an enclosing statement.", isEarly: true },
diff --git a/src/compiler/diagnosticMessages.json b/src/compiler/diagnosticMessages.json
index 240661277ee..390e6e79dc7 100644
--- a/src/compiler/diagnosticMessages.json
+++ b/src/compiler/diagnosticMessages.json
@@ -347,7 +347,8 @@
     },
     "A 'default' clause cannot appear more than once in a 'switch' statement.": {
         "category": "Error",
-        "code": 1113
+        "code": 1113,
+        "isEarly":  true
     },
     "Duplicate label '{0}'": {
         "category": "Error",
diff --git a/src/compiler/parser.ts b/src/compiler/parser.ts
index fa2df653765..d8f6cf636f3 100644
--- a/src/compiler/parser.ts
+++ b/src/compiler/parser.ts
@@ -4669,7 +4669,7 @@ module ts {
                 case SyntaxKind.SetAccessor:                    return checkSetAccessor(<MethodDeclaration>node);
                 case SyntaxKind.SourceFile:                     return checkSourceFile(<SourceFile>node);
                 //case SyntaxKind.ShorthandPropertyAssignment:    return checkShorthandPropertyAssignment(<ShorthandPropertyAssignment>node);
-                case SyntaxKind.SwitchStatement:                return checkSwitchStatement(<SwitchStatement>node);
+                //case SyntaxKind.SwitchStatement:                return checkSwitchStatement(<SwitchStatement>node);
                 case SyntaxKind.TaggedTemplateExpression:       return checkTaggedTemplateExpression(<TaggedTemplateExpression>node);
                 case SyntaxKind.ThrowStatement:                 return checkThrowStatement(<ThrowStatement>node);
                 case SyntaxKind.TypeReference:                  return checkTypeReference(<TypeReferenceNode>node);
@@ -5694,6 +5694,7 @@ module ts {
                         var start = skipTrivia(file.text, clause.pos);
                         var end = clause.statements.length > 0 ? clause.statements[0].pos : clause.end;
                         return grammarErrorAtPos(start, end - start, Diagnostics.A_default_clause_cannot_appear_more_than_once_in_a_switch_statement);
+
                     }
                 }
             }