diff --git a/packet_packer.go b/packet_packer.go
index af5c2b52c..bda585d96 100644
--- a/packet_packer.go
+++ b/packet_packer.go
@@ -33,6 +33,23 @@ func (p *packedPacket) ToAckHandlerPacket() *ackhandler.Packet {
 	}
 }
 
+func getMaxPacketSize(addr net.Addr) protocol.ByteCount {
+	maxSize := protocol.ByteCount(protocol.MinInitialPacketSize)
+	// If this is not a UDP address, we don't know anything about the MTU.
+	// Use the minimum size of an Initial packet as the max packet size.
+	if udpAddr, ok := addr.(*net.UDPAddr); ok {
+		// If ip is not an IPv4 address, To4 returns nil.
+		// Note that there might be some corner cases, where this is not correct.
+		// See https://stackoverflow.com/questions/22751035/golang-distinguish-ipv4-ipv6.
+		if udpAddr.IP.To4() == nil {
+			maxSize = protocol.MaxPacketSizeIPv6
+		} else {
+			maxSize = protocol.MaxPacketSizeIPv4
+		}
+	}
+	return maxSize
+}
+
 type sealingManager interface {
 	GetSealer() (protocol.EncryptionLevel, handshake.Sealer)
 	GetSealerForCryptoStream() (protocol.EncryptionLevel, handshake.Sealer)
@@ -84,19 +101,6 @@ func newPacketPacker(
 	perspective protocol.Perspective,
 	version protocol.VersionNumber,
 ) *packetPacker {
-	maxPacketSize := protocol.ByteCount(protocol.MinInitialPacketSize)
-	// If this is not a UDP address, we don't know anything about the MTU.
-	// Use the minimum size of an Initial packet as the max packet size.
-	if udpAddr, ok := remoteAddr.(*net.UDPAddr); ok {
-		// If ip is not an IPv4 address, To4 returns nil.
-		// Note that there might be some corner cases, where this is not correct.
-		// See https://stackoverflow.com/questions/22751035/golang-distinguish-ipv4-ipv6.
-		if udpAddr.IP.To4() == nil {
-			maxPacketSize = protocol.MaxPacketSizeIPv6
-		} else {
-			maxPacketSize = protocol.MaxPacketSizeIPv4
-		}
-	}
 	return &packetPacker{
 		cryptoSetup:           cryptoSetup,
 		divNonce:              divNonce,
@@ -108,7 +112,7 @@ func newPacketPacker(
 		streams:               streamFramer,
 		getPacketNumberLen:    getPacketNumberLen,
 		packetNumberGenerator: newPacketNumberGenerator(initialPacketNumber, protocol.SkipPacketAveragePeriodLength),
-		maxPacketSize:         maxPacketSize,
+		maxPacketSize:         getMaxPacketSize(remoteAddr),
 	}
 }
 
diff --git a/packet_packer_test.go b/packet_packer_test.go
index 985f99d96..02cba9edd 100644
--- a/packet_packer_test.go
+++ b/packet_packer_test.go
@@ -108,25 +108,19 @@ var _ = Describe("Packet packer", func() {
 	})
 
 	Context("determining the maximum packet size", func() {
-		connID := protocol.ConnectionID{1, 2, 3, 4, 5, 6, 7, 8}
-
 		It("uses the minimum initial size, if it can't determine if the remote address is IPv4 or IPv6", func() {
-			remoteAddr := &net.TCPAddr{}
-			packer = newPacketPacker(connID, connID, 1, nil, remoteAddr, nil, nil, nil, nil, protocol.PerspectiveServer, protocol.VersionWhatever)
-			Expect(packer.maxPacketSize).To(BeEquivalentTo(protocol.MinInitialPacketSize))
+			Expect(getMaxPacketSize(&net.TCPAddr{})).To(BeEquivalentTo(protocol.MinInitialPacketSize))
 		})
 
 		It("uses the maximum IPv4 packet size, if the remote address is IPv4", func() {
-			remoteAddr := &net.UDPAddr{IP: net.IPv4(11, 12, 13, 14), Port: 1337}
-			packer = newPacketPacker(connID, connID, 1, nil, remoteAddr, nil, nil, nil, nil, protocol.PerspectiveServer, protocol.VersionWhatever)
-			Expect(packer.maxPacketSize).To(BeEquivalentTo(protocol.MaxPacketSizeIPv4))
+			addr := &net.UDPAddr{IP: net.IPv4(11, 12, 13, 14), Port: 1337}
+			Expect(getMaxPacketSize(addr)).To(BeEquivalentTo(protocol.MaxPacketSizeIPv4))
 		})
 
 		It("uses the maximum IPv6 packet size, if the remote address is IPv6", func() {
 			ip := net.ParseIP("2001:0db8:85a3:0000:0000:8a2e:0370:7334")
-			remoteAddr := &net.UDPAddr{IP: ip, Port: 1337}
-			packer = newPacketPacker(connID, connID, 1, nil, remoteAddr, nil, nil, nil, nil, protocol.PerspectiveServer, protocol.VersionWhatever)
-			Expect(packer.maxPacketSize).To(BeEquivalentTo(protocol.MaxPacketSizeIPv6))
+			addr := &net.UDPAddr{IP: ip, Port: 1337}
+			Expect(getMaxPacketSize(addr)).To(BeEquivalentTo(protocol.MaxPacketSizeIPv6))
 		})
 	})