diff --git a/src/compiler/parser.ts b/src/compiler/parser.ts
index 84f05719151..b5cba38f39f 100644
--- a/src/compiler/parser.ts
+++ b/src/compiler/parser.ts
@@ -2850,8 +2850,8 @@ namespace ts {
                 if (sourceFile.languageVariant === LanguageVariant.JSX) {
                     let isArrowFunctionInJsx = lookAhead(() => {
                         let third = nextToken();
-                        let fourth = nextToken();
                         if (third === SyntaxKind.ExtendsKeyword) {
+                            let fourth = nextToken();
                             switch (fourth) {
                                 case SyntaxKind.EqualsToken:
                                 case SyntaxKind.GreaterThanToken: