From 0b24f02aae96a77cd9dbf40360dcd78b136a3005 Mon Sep 17 00:00:00 2001
From: Ron Buckton <ron.buckton@microsoft.com>
Date: Wed, 15 Nov 2017 17:12:05 -0800
Subject: [PATCH] Use correct base primitive type

---
 src/compiler/checker.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 8801502e091..227ff6f7d05 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -18842,7 +18842,7 @@ namespace ts {
                     // If the type parameter is constrained to the base primitive type we're checking for,
                     // consider this a literal context. For example, given a type parameter 'T extends string',
                     // this causes us to infer string literal types for T.
-                    if (constraint.flags & (TypeFlags.String | TypeFlags.Number | TypeFlags.Boolean | TypeFlags.Enum | TypeFlags.UniqueESSymbol)) {
+                    if (constraint.flags & (TypeFlags.String | TypeFlags.Number | TypeFlags.Boolean | TypeFlags.Enum | TypeFlags.Symbol)) {
                         return true;
                     }
                     contextualType = constraint;