diff --git a/excelize_test.go b/excelize_test.go
index 634364d..292b358 100644
--- a/excelize_test.go
+++ b/excelize_test.go
@@ -34,7 +34,7 @@ func TestExcelize(t *testing.T) {
 	// Test completion column.
 	f1.SetCellValue("Sheet2", "M2", nil)
 	// Test read cell value with given axis large than exists row.
-	f1.GetCellValue("Sheet2", "E13")
+	f1.GetCellValue("Sheet2", "E231")
 
 	for i := 1; i <= 300; i++ {
 		f1.SetCellStr("SHEET3", "c"+strconv.Itoa(i), strconv.Itoa(i))
@@ -78,6 +78,13 @@ func TestExcelize(t *testing.T) {
 		t.Log(err)
 	}
 
+	// Test set active sheet without BookViews and Sheets maps in xl/workbook.xml.
+	f4, err := OpenFile("./test/badWorkbook.xlsx")
+	f4.SetActiveSheet(2)
+	if err != nil {
+		t.Log(err)
+	}
+
 	// Test open a XLSX file with given illegal path.
 	_, err = OpenFile("./test/Workbook.xlsx")
 	if err != nil {
diff --git a/sheet.go b/sheet.go
index 66a72f5..c0e9287 100644
--- a/sheet.go
+++ b/sheet.go
@@ -42,7 +42,7 @@ func (f *File) setContentTypes(index int) {
 // Update sheet property by given index.
 func (f *File) setSheet(index int) {
 	var xlsx xlsxWorksheet
-	xlsx.Dimension.Ref = "A1"
+	xlsx.Dimension.Ref = `A1`
 	xlsx.SheetViews.SheetView = append(xlsx.SheetViews.SheetView, xlsxSheetView{
 		WorkbookViewID: 0,
 	})
@@ -85,7 +85,7 @@ func (f *File) addXlsxWorkbookRels(sheet int) {
 	content := f.readXlsxWorkbookRels()
 	rID := len(content.Relationships) + 1
 	ID := bytes.Buffer{}
-	ID.WriteString("rId")
+	ID.WriteString(`rId`)
 	ID.WriteString(strconv.Itoa(rID))
 	target := bytes.Buffer{}
 	target.WriteString(`worksheets/sheet`)
diff --git a/test/badWorkbook.xlsx b/test/badWorkbook.xlsx
new file mode 100644
index 0000000..f917a20
Binary files /dev/null and b/test/badWorkbook.xlsx differ