diff --git a/codecs/codecs.go b/codecs/codecs.go
index 4e49fc1..70628f8 100644
--- a/codecs/codecs.go
+++ b/codecs/codecs.go
@@ -125,7 +125,7 @@ func Keyframe(codec string, packet *rtp.Packet) (bool, bool) {
 			return false, false
 		} else if nalu <= 23 {
 			// simple NALU
-			return nalu == 5, true
+			return nalu == 7, true
 		} else if nalu == 24 || nalu == 25 || nalu == 26 || nalu == 27 {
 			// STAP-A, STAP-B, MTAP16 or MTAP24
 			i := 1