diff --git a/pkg/magic/producer.go b/pkg/magic/producer.go
index 8ed3e57a..5728da33 100644
--- a/pkg/magic/producer.go
+++ b/pkg/magic/producer.go
@@ -25,7 +25,7 @@ func Open(r io.Reader) (core.Producer, error) {
 	}
 
 	switch {
-	case bytes.HasPrefix(b, []byte(annexb.StartCode)):
+	case string(b) == annexb.StartCode:
 		return bitstream.Open(rd)
 
 	case bytes.HasPrefix(b, []byte{0xFF, 0xD8}):
@@ -37,7 +37,7 @@ func Open(r io.Reader) (core.Producer, error) {
 	case bytes.HasPrefix(b, []byte("--")):
 		return multipart.Open(rd)
 
-	case b[0] == 0xFF && b[1]&0xF7 == 0xF1:
+	case b[0] == 0xFF && (b[1] == 0xF1 || b[1] == 0xF9):
 		return aac.Open(rd)
 
 	case b[0] == mpegts.SyncByte: