diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index d087059d19e..e5b5299ff44 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -4379,8 +4379,8 @@ module ts {
         function getNarrowedTypeOfSymbol(symbol: Symbol, node: Node) {
             var type = getTypeOfSymbol(symbol);
             // Only narrow when symbol is variable of a structured type
-            if (node && node.parent && (symbol.flags & SymbolFlags.Variable && type.flags & TypeFlags.Structured)) {
-                loop: while (true) {
+            if (node && (symbol.flags & SymbolFlags.Variable && type.flags & TypeFlags.Structured)) {
+                loop: while (node.parent) {
                     var child = node;
                     node = node.parent;
                     var narrowedType = type;