diff --git a/pkg/format/rtpav1/decoder.go b/pkg/format/rtpav1/decoder.go
index fb24dd2e..91757d17 100644
--- a/pkg/format/rtpav1/decoder.go
+++ b/pkg/format/rtpav1/decoder.go
@@ -28,6 +28,14 @@ func joinFragments(fragments [][]byte, size int) []byte {
 	return ret
 }
 
+func tuSize(tu [][]byte) int {
+	s := 0
+	for _, obu := range tu {
+		s += len(obu)
+	}
+	return s
+}
+
 // Decoder is a RTP/AV1 decoder.
 // Specification: https://aomediacodec.github.io/av1-rtp-spec/
 type Decoder struct {
@@ -107,15 +115,7 @@ func (d *Decoder) decodeOBUs(pkt *rtp.Packet) ([][]byte, error) {
 		if av1header.Y {
 			elementCount := len(av1header.OBUElements)
 
-			d.fragmentsSize += len(av1header.OBUElements[elementCount-1])
-
-			if d.fragmentsSize > av1.MaxTemporalUnitSize {
-				errSize := d.fragmentsSize
-				d.resetFragments()
-				return nil, fmt.Errorf("temporal unit size (%d) is too big, maximum is %d",
-					errSize, av1.MaxTemporalUnitSize)
-			}
-
+			d.fragmentsSize = len(av1header.OBUElements[elementCount-1])
 			d.fragments = append(d.fragments, av1header.OBUElements[elementCount-1])
 			av1header.OBUElements = av1header.OBUElements[:elementCount-1]
 			d.fragmentNextSeqNum = pkt.SequenceNumber + 1
@@ -151,11 +151,7 @@ func (d *Decoder) Decode(pkt *rtp.Packet) ([][]byte, error) {
 			errCount, av1.MaxOBUsPerTemporalUnit)
 	}
 
-	addSize := 0
-
-	for _, obu := range obus {
-		addSize += len(obu)
-	}
+	addSize := tuSize(obus)
 
 	if (d.frameBufferSize + addSize) > av1.MaxTemporalUnitSize {
 		errSize := d.frameBufferSize + addSize
diff --git a/pkg/format/rtpav1/decoder_test.go b/pkg/format/rtpav1/decoder_test.go
index a16bee8d..182518a8 100644
--- a/pkg/format/rtpav1/decoder_test.go
+++ b/pkg/format/rtpav1/decoder_test.go
@@ -1,6 +1,7 @@
 package rtpav1
 
 import (
+	"bytes"
 	"errors"
 	"testing"
 
@@ -33,6 +34,48 @@ func TestDecode(t *testing.T) {
 	}
 }
 
+func TestDecoderErrorTUSize(t *testing.T) {
+	d := &Decoder{}
+	err := d.Init()
+	require.NoError(t, err)
+
+	size := 0
+	i := uint16(0)
+
+	for size < av1.MaxTemporalUnitSize {
+		var header byte
+		if i == 0 {
+			header = 0b01000000
+		} else {
+			header = 0b11000000
+		}
+
+		fragmentLenLEB := av1.LEB128(1400)
+		buf := make([]byte, fragmentLenLEB.MarshalSize())
+		fragmentLenLEB.MarshalTo(buf)
+
+		payload := append([]byte{header}, buf...)
+		payload = append(payload, bytes.Repeat([]byte{1, 2, 3, 4}, 1400/4)...)
+
+		_, err = d.Decode(&rtp.Packet{
+			Header: rtp.Header{
+				Version:        2,
+				Marker:         false,
+				PayloadType:    96,
+				SequenceNumber: 17645 + i,
+				Timestamp:      2289527317,
+				SSRC:           0x9dbb7812,
+			},
+			Payload: payload,
+		})
+
+		size += 1400
+		i++
+	}
+
+	require.EqualError(t, err, "temporal unit size (3145800) is too big, maximum is 3145728")
+}
+
 func TestDecoderErrorOBUCount(t *testing.T) {
 	d := &Decoder{}
 	err := d.Init()
diff --git a/pkg/format/rtph264/decoder.go b/pkg/format/rtph264/decoder.go
index 8ccc781b..519c045d 100644
--- a/pkg/format/rtph264/decoder.go
+++ b/pkg/format/rtph264/decoder.go
@@ -38,6 +38,14 @@ func isAllZero(buf []byte) bool {
 	return true
 }
 
+func auSize(au [][]byte) int {
+	s := 0
+	for _, nalu := range au {
+		s += len(nalu)
+	}
+	return s
+}
+
 // Decoder is a RTP/H264 decoder.
 // Specification: https://datatracker.ietf.org/doc/html/rfc6184
 type Decoder struct {
@@ -223,11 +231,7 @@ func (d *Decoder) Decode(pkt *rtp.Packet) ([][]byte, error) {
 			errCount, h264.MaxNALUsPerAccessUnit)
 	}
 
-	addSize := 0
-
-	for _, nalu := range nalus {
-		addSize += len(nalu)
-	}
+	addSize := auSize(nalus)
 
 	if (d.frameBufferSize + addSize) > h264.MaxAccessUnitSize {
 		errSize := d.frameBufferSize + addSize
diff --git a/pkg/format/rtph265/decoder.go b/pkg/format/rtph265/decoder.go
index 4777a06c..837af18e 100644
--- a/pkg/format/rtph265/decoder.go
+++ b/pkg/format/rtph265/decoder.go
@@ -28,6 +28,14 @@ func joinFragments(fragments [][]byte, size int) []byte {
 	return ret
 }
 
+func auSize(au [][]byte) int {
+	s := 0
+	for _, nalu := range au {
+		s += len(nalu)
+	}
+	return s
+}
+
 // Decoder is a RTP/H265 decoder.
 // Specification: https://datatracker.ietf.org/doc/html/rfc7798
 type Decoder struct {
@@ -182,11 +190,7 @@ func (d *Decoder) Decode(pkt *rtp.Packet) ([][]byte, error) {
 			errCount, h265.MaxNALUsPerAccessUnit)
 	}
 
-	addSize := 0
-
-	for _, nalu := range nalus {
-		addSize += len(nalu)
-	}
+	addSize := auSize(nalus)
 
 	if (d.frameBufferSize + addSize) > h265.MaxAccessUnitSize {
 		errSize := d.frameBufferSize + addSize