diff --git a/mask.go b/mask.go
index 687a10d..c9c6b81 100644
--- a/mask.go
+++ b/mask.go
@@ -126,7 +126,8 @@ func rule2(mat *matrix.Matrix) int {
 }
 
 // 如果存在看起来类似于取景器模式的模式，则第三规则给QR码一个大的惩罚
-// dark-light-dark-dark-dark-light-dark // 1011101 0000 or 0000 1011101
+// dark-light-dark-dark-dark-light-dark
+// 1011101 0000 or 0000 1011101
 func rule3(mat *matrix.Matrix) int {
 	var (
 		score      int
@@ -204,27 +205,29 @@ func abs(x int) int {
 }
 
 type mask struct {
-	mat  *matrix.Matrix    // matrix
-	mode maskPatternModulo // mode
+	mat      *matrix.Matrix    // matrix
+	mode     maskPatternModulo // mode
+	moduloFn moduloFunc        // moduloFn masking function
 }
 
 // newMask ...
-func newMask(m *matrix.Matrix, mode maskPatternModulo) *mask {
-	mask := &mask{
-		mat:  m.Copy(),
-		mode: mode,
+func newMask(mat *matrix.Matrix, mode maskPatternModulo) *mask {
+	m := &mask{
+		mat:      mat.Copy(),
+		mode:     mode,
+		moduloFn: getModuloFunc(mode),
 	}
-	mask.init()
-	return mask
+	m.masking()
+
+	return m
 }
 
 // moduloFunc to define what's modulo func
 type moduloFunc func(int, int) bool
 
-// init generate maks by mode
-func (m *mask) init() {
-	var f moduloFunc
-	switch m.mode {
+func getModuloFunc(mode maskPatternModulo) (f moduloFunc) {
+	f = nil
+	switch mode {
 	case modulo0:
 		f = modulo0Func
 	case modulo1:
@@ -243,13 +246,23 @@ func (m *mask) init() {
 		f = modulo7Func
 	}
 
+	return
+}
+
+// init generate maks by mode
+func (m *mask) masking() {
+	moduloFn := m.moduloFn
+	if moduloFn == nil {
+		panic("impossible panic, contact maintainer plz")
+	}
+
 	m.mat.Iterate(matrix.ROW, func(x, y int, s matrix.State) {
 		// skip the function modules
 		if state, _ := m.mat.Get(x, y); state != matrix.StateInit {
 			_ = m.mat.Set(x, y, matrix.StateInit)
 			return
 		}
-		if f(x, y) {
+		if moduloFn(x, y) {
 			_ = m.mat.Set(x, y, matrix.StateTrue)
 		} else {
 			_ = m.mat.Set(x, y, matrix.StateFalse)
diff --git a/mask_test.go b/mask_test.go
index 41cd413..1a4ea5a 100644
--- a/mask_test.go
+++ b/mask_test.go
@@ -3,21 +3,29 @@ package qrcode
 import (
 	"testing"
 
+	"github.com/stretchr/testify/require"
+
 	"github.com/yeqown/go-qrcode/matrix"
 )
 
 func TestMask(t *testing.T) {
-	qrc, _ := New("baidu.com google.com qq.com sina.com apple.com")
-	qrc.initMatrix()
+	qrc := &QRCode{
+		content:      "baidu.com google.com qq.com sina.com apple.com",
+		mode:         DefaultConfig().EncMode,
+		ecLv:         DefaultConfig().EcLevel,
+		needAnalyze:  true,
+		outputOption: defaultOutputImageOption(),
+	}
+	err := qrc.init()
+	require.NoError(t, err)
 
 	var stateInitCnt int
-
 	qrc.mat.Iterate(matrix.ROW, func(x, y int, s matrix.State) {
 		if s == matrix.StateInit {
 			stateInitCnt++
 		}
 	})
-	t.Logf("all state init count: %d", stateInitCnt)
+	t.Logf("all StateInit block count: %d", stateInitCnt)
 
 	cpyMat := qrc.mat.Copy()
 	_ = drawAndSaveToFile("./testdata/mask_origin.jpeg", *cpyMat, nil)
diff --git a/qrcode.go b/qrcode.go
index 17ac6d3..838521e 100644
--- a/qrcode.go
+++ b/qrcode.go
@@ -86,7 +86,7 @@ func NewWithConfig(text string, encOpts *Config, opts ...ImageOption) (*QRCode,
 }
 
 // QRCode contains fields to generate QRCode matrix, outputImageOptions to Draw image,
-// and etc.
+// etc.
 type QRCode struct {
 	content string // input text content
 	rawData []byte // raw Data to transfer
@@ -99,7 +99,7 @@ type QRCode struct {
 	ver     int      // version num
 	ecLv    ecLevel  // error correction level
 	mode    encMode  // encMode
-	encoder *encoder // encoder ptr to call it's methods ~
+	encoder *encoder // encoder ptr to call its methods ~
 
 	needAnalyze bool // auto analyze form content or specified `mode, recoverLv, ver`
 
@@ -116,7 +116,7 @@ func (q *QRCode) init() error {
 	//})
 	q.rawData = []byte(q.content)
 	if q.needAnalyze {
-		// analyze the input data to choose adapt version
+		// analyze the input data to choose to adapt version
 		if err := q.analyze(); err != nil {
 			return fmt.Errorf("could not analyze the data: %v", err)
 		}
@@ -160,6 +160,9 @@ func (q *QRCode) init() error {
 	// append remainder bits
 	q.dataBSet.AppendNumBools(q.v.RemainderBits, false)
 
+	// initial the 2d matrix
+	q.prefillMatrix()
+
 	return nil
 }
 
@@ -329,9 +332,9 @@ func (q *QRCode) arrangeBits(dataBlocks []dataBlock, ecBlocks []ecBlock) {
 	debugLogf("ec bitsets: %s", q.ecBSet.String())
 }
 
-// InitMatrix with version info: ref to:
+// prefillMatrix with version info: ref to:
 // http://www.thonky.com/qr-code-tutorial/module-placement-matrix
-func (q *QRCode) initMatrix() {
+func (q *QRCode) prefillMatrix() {
 	dimension := q.v.Dimension()
 	if q.mat == nil {
 		q.mat = matrix.New(dimension, dimension)
@@ -515,6 +518,10 @@ func reserveFormatBlock(m *matrix.Matrix, dimension int) {
 		_ = m.Set(dimension-pos, 8, matrix.StateFormat) // top-right-row
 		_ = m.Set(8, dimension-pos, matrix.StateFormat) // bottom-left-column
 	}
+
+	// fix(@yeqown): b4b5ae3 reduced two format reversed blocks on top-left-column and top-left-row.
+	_ = m.Set(0, 8, matrix.StateFormat)
+	_ = m.Set(8, 0, matrix.StateFormat)
 }
 
 // reserveVersionBlock maintain the position in matrix for version info
@@ -666,9 +673,6 @@ func (q *QRCode) masking() {
 
 	dimension := q.v.Dimension()
 
-	// initial the 2d matrix
-	q.initMatrix()
-
 	// init mask and mats
 	for i := 0; i < 8; i++ {
 		masks[i] = newMask(q.mat, maskPatternModulo(i))