diff --git a/lib/hls/hls_parser.js b/lib/hls/hls_parser.js
index c8e26ce720..e0037d7844 100644
--- a/lib/hls/hls_parser.js
+++ b/lib/hls/hls_parser.js
@@ -2915,7 +2915,11 @@ shaka.hls.HlsParser = class {
         if (item.name == 'EXT-X-PRELOAD-HINT') {
           partial.markAsPreload();
         }
-        if (item.getAttributeValue('INDEPENDENT') != 'YES') {
+        // The spec doesn't say that we can assume INDEPENDENT=YES for the
+        // first partial segment. It does call the flag "optional", though, and
+        // that cases where there are no such flags on any partial segments, it
+        // is sensible to assume the first one is independent.
+        if (item.getAttributeValue('INDEPENDENT') != 'YES' && i > 0) {
           partial.markAsNonIndependent();
         }
         partialSegmentRefs.push(partial);