diff --git a/codec/h264/lex.go b/codec/h264/lex.go
index 0883c160..a5b94bb8 100644
--- a/codec/h264/lex.go
+++ b/codec/h264/lex.go
@@ -274,17 +274,17 @@ func (l *RTPLexer) handleFUA(d []byte) {
 		d = d[2:]
 	}
 
-	switch {
-	case start && !end:
+	if start {
+		if end {
+			panic("bad fragmentation packet")
+		}
 		l.frag = true
 		l.writeWithPrefix(d)
-	case !start && end:
-		l.frag = false
-		fallthrough
-	case !start && !end:
+	} else {
+		if end {
+			l.frag = false
+		}
 		l.writeNoPrefix(d)
-	default:
-		panic("bad fragmentation packet")
 	}
 }