From 5ad46b180b0ec0b1b51df234acf0d5ededf457c3 Mon Sep 17 00:00:00 2001
From: Anders Hejlsberg <andersh@microsoft.com>
Date: Wed, 5 Jun 2019 16:53:42 -0700
Subject: [PATCH] Fix minor issue

---
 src/compiler/checker.ts | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 01cb7c9fea2..f2a34ae9a1a 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -6444,7 +6444,8 @@ namespace ts {
                 for (const declaration of symbol.declarations) {
                     if (declaration.kind === SyntaxKind.EnumDeclaration) {
                         for (const member of (<EnumDeclaration>declaration).members) {
-                            const memberType = getFreshTypeOfLiteralType(getLiteralType(getEnumMemberValue(member) || 0, enumCount, getSymbolOfNode(member)));
+                            const value = getEnumMemberValue(member);
+                            const memberType = getFreshTypeOfLiteralType(getLiteralType(value !== undefined ? value : 0, enumCount, getSymbolOfNode(member)));
                             getSymbolLinks(getSymbolOfNode(member)).declaredType = memberType;
                             memberTypeList.push(getRegularTypeOfLiteralType(memberType));
                         }