diff --git a/src/compiler/parser.ts b/src/compiler/parser.ts
index f9be81446f..57129829ad 100644
--- a/src/compiler/parser.ts
+++ b/src/compiler/parser.ts
@@ -5252,10 +5252,15 @@ namespace ts {
             return parseIdentifier();
         }
 
-        function parseVariableDeclaration(): VariableDeclaration {
+        function parseVariableDeclarationAllowExclamation() {
+            return parseVariableDeclaration(/*allowExclamation*/ true);
+        }
+
+        function parseVariableDeclaration(allowExclamation?: boolean): VariableDeclaration {
             const node = <VariableDeclaration>createNode(SyntaxKind.VariableDeclaration);
             node.name = parseIdentifierOrPattern();
-            if (node.name.kind === SyntaxKind.Identifier && token() === SyntaxKind.ExclamationToken && !scanner.hasPrecedingLineBreak()) {
+            if (allowExclamation && node.name.kind === SyntaxKind.Identifier &&
+                token() === SyntaxKind.ExclamationToken && !scanner.hasPrecedingLineBreak()) {
                 node.exclamationToken = parseTokenNode();
             }
             node.type = parseTypeAnnotation();
@@ -5299,7 +5304,8 @@ namespace ts {
                 const savedDisallowIn = inDisallowInContext();
                 setDisallowInContext(inForStatementInitializer);
 
-                node.declarations = parseDelimitedList(ParsingContext.VariableDeclarations, parseVariableDeclaration);
+                node.declarations = parseDelimitedList(ParsingContext.VariableDeclarations,
+                    inForStatementInitializer ? parseVariableDeclaration : parseVariableDeclarationAllowExclamation);
 
                 setDisallowInContext(savedDisallowIn);
             }