diff --git a/library/rtsp/src/main/java/com/google/android/exoplayer2/source/rtsp/reader/RtpVp8Reader.java b/library/rtsp/src/main/java/com/google/android/exoplayer2/source/rtsp/reader/RtpVp8Reader.java
index 6a739a4ba0..fa5fdb8af2 100644
--- a/library/rtsp/src/main/java/com/google/android/exoplayer2/source/rtsp/reader/RtpVp8Reader.java
+++ b/library/rtsp/src/main/java/com/google/android/exoplayer2/source/rtsp/reader/RtpVp8Reader.java
@@ -214,7 +214,7 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
             fragmentedSampleSizeBytes,
             /* offset= */ 0,
             /* cryptoData= */ null);
-    fragmentedSampleSizeBytes = 0;
+    fragmentedSampleSizeBytes = C.LENGTH_UNSET;
     fragmentedSampleTimeUs = C.TIME_UNSET;
     gotFirstPacketOfVp8Frame = false;
   }