diff --git a/public_header_test.go b/public_header_test.go
index 18196505..5497afb1 100644
--- a/public_header_test.go
+++ b/public_header_test.go
@@ -2,22 +2,82 @@ package quic
 
 import (
 	"bytes"
+	"encoding/binary"
 
 	. "github.com/onsi/ginkgo"
 	. "github.com/onsi/gomega"
 )
 
 var _ = Describe("Public Header", func() {
-	It("parses intial client header", func() {
-		b := bytes.NewReader([]byte{0xd, 0xf6, 0x19, 0x86, 0x66, 0x9b, 0x9f, 0xfa, 0x4c, 0x51, 0x30, 0x33, 0x30, 0x1})
-		publicHeader, err := ParsePublicHeader(b)
-		Expect(err).ToNot(HaveOccurred())
-		Expect(publicHeader.VersionFlag).To(BeTrue())
-		Expect(publicHeader.ResetFlag).To(BeFalse())
-		Expect(publicHeader.ConnectionIDLength).To(Equal(uint8(8)))
-		Expect(publicHeader.ConnectionID).ToNot(BeZero())
-		Expect(publicHeader.QuicVersion).To(Equal(uint32(0x51303330)))
-		Expect(publicHeader.PacketNumberLength).To(Equal(uint8(1)))
-		Expect(publicHeader.PacketNumber).To(Equal(uint64(1)))
+	Context("when parsing", func() {
+		It("accepts a sample client header", func() {
+			b := bytes.NewReader([]byte{0x0d, 0xf6, 0x19, 0x86, 0x66, 0x9b, 0x9f, 0xfa, 0x4c, 0x51, 0x30, 0x33, 0x30, 0x01})
+			publicHeader, err := ParsePublicHeader(b)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(publicHeader.VersionFlag).To(BeTrue())
+			Expect(publicHeader.ResetFlag).To(BeFalse())
+			Expect(publicHeader.ConnectionIDLength).To(Equal(uint8(8)))
+			Expect(publicHeader.ConnectionID).To(Equal(uint64(0xf61986669b9ffa4c)))
+			Expect(publicHeader.QuicVersion).To(Equal(binary.BigEndian.Uint32([]byte("Q030"))))
+			Expect(publicHeader.PacketNumberLength).To(Equal(uint8(1)))
+			Expect(publicHeader.PacketNumber).To(Equal(uint64(1)))
+			Expect(b.Len()).To(BeZero())
+		})
+
+		It("accepts 4-byte connection IDs", func() {
+			b := bytes.NewReader([]byte{0x08, 0x9b, 0x9f, 0xfa, 0x4c, 0x01})
+			publicHeader, err := ParsePublicHeader(b)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(publicHeader.VersionFlag).To(BeFalse())
+			Expect(publicHeader.ConnectionIDLength).To(Equal(uint8(4)))
+			Expect(publicHeader.ConnectionID).To(Equal(uint64(0x9b9ffa4c)))
+			Expect(b.Len()).To(BeZero())
+		})
+
+		It("accepts 1-byte connection IDs", func() {
+			b := bytes.NewReader([]byte{0x04, 0x4c, 0x01})
+			publicHeader, err := ParsePublicHeader(b)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(publicHeader.VersionFlag).To(BeFalse())
+			Expect(publicHeader.ConnectionIDLength).To(Equal(uint8(1)))
+			Expect(publicHeader.ConnectionID).To(Equal(uint64(0x4c)))
+			Expect(b.Len()).To(BeZero())
+		})
+
+		It("accepts 0-byte connection ID", func() {
+			b := bytes.NewReader([]byte{0x00, 0x01})
+			publicHeader, err := ParsePublicHeader(b)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(publicHeader.VersionFlag).To(BeFalse())
+			Expect(publicHeader.ConnectionIDLength).To(Equal(uint8(0)))
+			Expect(b.Len()).To(BeZero())
+		})
+
+		It("accepts 2-byte packet numbers", func() {
+			b := bytes.NewReader([]byte{0x10, 0xde, 0xca})
+			publicHeader, err := ParsePublicHeader(b)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(publicHeader.PacketNumberLength).To(Equal(uint8(2)))
+			Expect(publicHeader.PacketNumber).To(Equal(uint64(0xdeca)))
+			Expect(b.Len()).To(BeZero())
+		})
+
+		It("accepts 4-byte packet numbers", func() {
+			b := bytes.NewReader([]byte{0x20, 0xde, 0xca, 0xfb, 0xad})
+			publicHeader, err := ParsePublicHeader(b)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(publicHeader.PacketNumberLength).To(Equal(uint8(4)))
+			Expect(publicHeader.PacketNumber).To(Equal(uint64(0xdecafbad)))
+			Expect(b.Len()).To(BeZero())
+		})
+
+		It("accepts 6-byte packet numbers", func() {
+			b := bytes.NewReader([]byte{0x30, 0xde, 0xca, 0xfb, 0xad, 0x42, 0x23})
+			publicHeader, err := ParsePublicHeader(b)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(publicHeader.PacketNumberLength).To(Equal(uint8(6)))
+			Expect(publicHeader.PacketNumber).To(Equal(uint64(0xdecafbad4223)))
+			Expect(b.Len()).To(BeZero())
+		})
 	})
 })