diff --git a/library/src/main/java/com/google/android/exoplayer2/source/hls/HlsChunkSource.java b/library/src/main/java/com/google/android/exoplayer2/source/hls/HlsChunkSource.java
index 53d9e70d76..a23ab3bae7 100644
--- a/library/src/main/java/com/google/android/exoplayer2/source/hls/HlsChunkSource.java
+++ b/library/src/main/java/com/google/android/exoplayer2/source/hls/HlsChunkSource.java
@@ -440,6 +440,10 @@ import java.util.Locale;
     }
     HlsMediaPlaylist oldMediaPlaylist = variantPlaylists[oldVariantIndex];
     HlsMediaPlaylist newMediaPlaylist = variantPlaylists[newVariantIndex];
+    if (previousChunkIndex < oldMediaPlaylist.mediaSequence) {
+      // We have fallen behind the live window.
+      return newMediaPlaylist.mediaSequence - 1;
+    }
     double offsetToLiveInstantSecs = 0;
     for (int i = previousChunkIndex - oldMediaPlaylist.mediaSequence;
          i < oldMediaPlaylist.segments.size(); i++) {