diff --git a/packet_unpacker.go b/packet_unpacker.go
index 95b9d4f79..1e1682dce 100644
--- a/packet_unpacker.go
+++ b/packet_unpacker.go
@@ -37,7 +37,7 @@ func (u *packetUnpacker) Unpack(publicHeaderBinary []byte, hdr *publicHeader, r
 	}
 	entropyBit := privateFlag&0x01 > 0
 
-	fs := []frames.Frame{}
+	fs := make([]frames.Frame, 0, 1)
 
 	// Read all frames in the packet
 ReadLoop:
diff --git a/session.go b/session.go
index 7c0bbc285..206c67c9b 100644
--- a/session.go
+++ b/session.go
@@ -545,6 +545,10 @@ func (s *Session) sendConnectionClose(quicErr *qerr.QuicError) error {
 }
 
 func (s *Session) logPacket(packet *packedPacket) {
+	if !utils.Debug() {
+		// We don't need to allocate the slices for calling the format functions
+		return
+	}
 	utils.Debugf("-> Sending packet 0x%x (%d bytes)", packet.number, len(packet.raw))
 	for _, frame := range packet.frames {
 		if streamFrame, isStreamFrame := frame.(*frames.StreamFrame); isStreamFrame {
diff --git a/utils/log.go b/utils/log.go
index 864a48956..c82f6f477 100644
--- a/utils/log.go
+++ b/utils/log.go
@@ -58,3 +58,8 @@ func Errorf(format string, args ...interface{}) {
 		mutex.Unlock()
 	}
 }
+
+// Debug returns true if the log level is LogLevelDebug
+func Debug() bool {
+	return logLevel == LogLevelDebug
+}