diff --git a/third_party/blink/web_tests/external/wpt/media-source/SourceBuffer-writeHead.html b/third_party/blink/web_tests/external/wpt/media-source/SourceBuffer-writeHead.html
index 75b9bca81145..56b93e84c945 100644
--- a/third_party/blink/web_tests/external/wpt/media-source/SourceBuffer-writeHead.html
+++ b/third_party/blink/web_tests/external/wpt/media-source/SourceBuffer-writeHead.html
@@ -75,7 +75,7 @@
                     expectedWriteHead = expectedWriteHead + segmentLength;
                     assert_equals(sourceBuffer.writeHead, expectedWriteHead);
                     index = index - 1;
-                    if (index == 0) {
+                    if (index <= 0) {
                         test.done();
                         return;
                     }