diff --git a/group/group_test.go b/group/group_test.go
index 1d8bb89..261517d 100644
--- a/group/group_test.go
+++ b/group/group_test.go
@@ -7,6 +7,8 @@ import (
 	"sort"
 	"testing"
 	"time"
+
+	"github.com/pion/webrtc/v4"
 )
 
 func TestGroup(t *testing.T) {
@@ -348,3 +350,32 @@ func TestValidGroupName(t *testing.T) {
 		}
 	}
 }
+
+func TestPayloadTypeDiscontiguous(t *testing.T) {
+	names := []string{
+		"vp8", "vp9", "av1", "h264",
+		"opus", "g722", "pcmu", "pcma",
+	}
+
+	m := make(map[webrtc.PayloadType]bool)
+
+	for _, n := range names {
+		codec, err := codecsFromName(n)
+		if err != nil {
+			t.Errorf("%v: %v", n, err)
+			continue
+		}
+		pt, err := CodecPayloadType(codec[0].RTPCodecCapability)
+		if err != nil {
+			t.Errorf("%v: %v", codec, err)
+			continue
+		}
+		m[pt] = true
+	}
+
+	for pt := range m {
+		if m[pt+1] {
+			t.Errorf("%v and %v are both defined", pt, pt+1)
+		}
+	}
+}