diff --git a/frame.go b/frame.go
index 70f810f1c..43dd22b2a 100644
--- a/frame.go
+++ b/frame.go
@@ -6,6 +6,7 @@ import (
 )
 
 // A StreamFrame of QUIC
+// TODO: Maybe remove unneeded stuff, e.g. lengths?
 type StreamFrame struct {
 	FinBit            bool
 	DataLengthPresent bool
@@ -33,26 +34,22 @@ func ParseStreamFrame(r *bytes.Reader) (*StreamFrame, error) {
 	}
 	frame.StreamIDLength = typeByte&0x03 + 1
 
-	sid, err := readUint64(r, frame.StreamIDLength)
+	sid, err := readUintN(r, frame.StreamIDLength)
 	if err != nil {
 		return nil, err
 	}
 	frame.StreamID = uint32(sid)
 
-	frame.Offset, err = readUint64(r, frame.OffsetLength)
+	frame.Offset, err = readUintN(r, frame.OffsetLength)
 	if err != nil {
 		return nil, err
 	}
 
 	if frame.DataLengthPresent {
-		var b1, b2 byte
-		if b1, err = r.ReadByte(); err != nil {
+		frame.DataLength, err = readUint16(r)
+		if err != nil {
 			return nil, err
 		}
-		if b2, err = r.ReadByte(); err != nil {
-			return nil, err
-		}
-		frame.DataLength = uint16(b1) + uint16(b2)<<8
 	}
 
 	if frame.DataLength == 0 {
diff --git a/public_header.go b/public_header.go
index 88eea0d30..b56619923 100644
--- a/public_header.go
+++ b/public_header.go
@@ -47,7 +47,7 @@ func ParsePublicHeader(b io.ByteReader) (*PublicHeader, error) {
 	}
 
 	// Connection ID
-	header.ConnectionID, err = readUint64(b, header.ConnectionIDLength)
+	header.ConnectionID, err = readUintN(b, header.ConnectionIDLength)
 	if err != nil {
 		return nil, err
 	}
@@ -55,7 +55,7 @@ func ParsePublicHeader(b io.ByteReader) (*PublicHeader, error) {
 	// Version (optional)
 	if header.VersionFlag {
 		var v uint64
-		v, err = readUint64(b, 4)
+		v, err = readUintN(b, 4)
 		if err != nil {
 			return nil, err
 		}
@@ -63,7 +63,7 @@ func ParsePublicHeader(b io.ByteReader) (*PublicHeader, error) {
 	}
 
 	// Packet number
-	header.PacketNumber, err = readUint64(b, header.PacketNumberLength)
+	header.PacketNumber, err = readUintN(b, header.PacketNumberLength)
 	if err != nil {
 		return nil, err
 	}
diff --git a/utils.go b/utils.go
index 6f74a9c51..c8293a3d1 100644
--- a/utils.go
+++ b/utils.go
@@ -2,7 +2,7 @@ package quic
 
 import "io"
 
-func readUint64(b io.ByteReader, length uint8) (uint64, error) {
+func readUintN(b io.ByteReader, length uint8) (uint64, error) {
 	var res uint64
 	for i := uint8(0); i < length; i++ {
 		bt, err := b.ReadByte()
@@ -13,3 +13,33 @@ func readUint64(b io.ByteReader, length uint8) (uint64, error) {
 	}
 	return res, nil
 }
+
+func readUint32(b io.ByteReader) (uint32, error) {
+	var b1, b2, b3, b4 uint8
+	var err error
+	if b1, err = b.ReadByte(); err != nil {
+		return 0, err
+	}
+	if b2, err = b.ReadByte(); err != nil {
+		return 0, err
+	}
+	if b3, err = b.ReadByte(); err != nil {
+		return 0, err
+	}
+	if b4, err = b.ReadByte(); err != nil {
+		return 0, err
+	}
+	return uint32(b1) + uint32(b2)<<8 + uint32(b3)<<16 + uint32(b4)<<24, nil
+}
+
+func readUint16(b io.ByteReader) (uint16, error) {
+	var b1, b2 uint8
+	var err error
+	if b1, err = b.ReadByte(); err != nil {
+		return 0, err
+	}
+	if b2, err = b.ReadByte(); err != nil {
+		return 0, err
+	}
+	return uint16(b1) + uint16(b2)<<8, nil
+}