diff --git a/src/browser/Linkifier.test.ts b/src/browser/Linkifier.test.ts
index a0755745e..a07f69ed2 100644
--- a/src/browser/Linkifier.test.ts
+++ b/src/browser/Linkifier.test.ts
@@ -210,7 +210,7 @@ describe('Linkifier', () => {
         let count = 0;
         linkifier.registerLinkMatcher(/test/, () => assert.fail(), {
           validationCallback: (url, cb) => {
-            ++count;
+            count++;
             if (count === 2) {
               done();
             }