diff --git a/codecs/h266_packet.go b/codecs/h266_packet.go
index 17e39e7..f816aaa 100644
--- a/codecs/h266_packet.go
+++ b/codecs/h266_packet.go
@@ -662,6 +662,7 @@ func (d *H266Depacketizer) Unmarshal(packet []byte) ([]byte, error) { //nolint:
 			if err != nil {
 				return nil, err
 			}
+			rebuilt.donl = nil
 			output = append(output, rebuilt.packetize(make([]byte, 0))...)
 			d.partials = d.partials[:0]
 
@@ -690,6 +691,7 @@ func (d *H266Depacketizer) Unmarshal(packet []byte) ([]byte, error) { //nolint:
 		}
 		for _, p := range aggregated {
 			output = append(output, annexbNALUStartCode...)
+			p.donl = nil
 			output = p.packetize(output)
 		}
 
@@ -702,6 +704,7 @@ func (d *H266Depacketizer) Unmarshal(packet []byte) ([]byte, error) { //nolint:
 		return nil, errNalCorrupted
 	}
 
+	single.donl = nil
 	output = single.packetize(output)
 
 	return output, nil
diff --git a/codecs/h266_packet_test.go b/codecs/h266_packet_test.go
index db45dcc..9791773 100644
--- a/codecs/h266_packet_test.go
+++ b/codecs/h266_packet_test.go
@@ -540,7 +540,7 @@ func TestH266Depacketizer_Roundtrip(t *testing.T) {
 			}
 
 			emitH266Nalus(p, func(b []byte) {
-				parsed, err := parseH266Packet(b, withDonl)
+				parsed, err := parseH266Packet(b, false)
 				assert.Nil(t, err)
 				if err != nil {
 					return
@@ -567,8 +567,10 @@ func TestH266Depacketizer_Roundtrip(t *testing.T) {
 	// with DONL
 
 	basicPacket.donl = &testDonl
+	packetized := basicPacket.packetize(make([]byte, 0))
+	basicPacket.donl = nil
 
-	testDepacketizer([][]byte{basicPacket.packetize(make([]byte, 0))}, []isH266Packet{basicPacket}, true)
+	testDepacketizer([][]byte{packetized}, []isH266Packet{basicPacket}, true)
 
 	// Multiple NALs aggregated
 
@@ -599,6 +601,9 @@ func TestH266Depacketizer_Roundtrip(t *testing.T) {
 	assert.Nil(t, err)
 	donlAggregationPacketized := donlAggregation.packetize(make([]byte, 0))
 
+	firstPacket.donl = nil
+	secondPacket.donl = nil
+
 	testDepacketizer([][]byte{donlAggregationPacketized}, []isH266Packet{firstPacket, secondPacket}, true)
 
 	// Large NAL that gets fragmented
@@ -636,5 +641,7 @@ func TestH266Depacketizer_Roundtrip(t *testing.T) {
 		donlFragmentsPacketized = append(donlFragmentsPacketized, f.packetize(make([]byte, 0)))
 	}
 
+	largePacket.donl = nil
+
 	testDepacketizer(donlFragmentsPacketized, []isH266Packet{largePacket}, true)
 }