diff --git a/cwriter/clear_lines_bench_test.go b/cwriter/clear_lines_bench_test.go
new file mode 100644
index 0000000..af80be9
--- /dev/null
+++ b/cwriter/clear_lines_bench_test.go
@@ -0,0 +1,39 @@
+package cwriter
+
+import (
+	"bytes"
+	"fmt"
+	"io/ioutil"
+	"strconv"
+	"testing"
+)
+
+func BenchmarkWithFprintf(b *testing.B) {
+	cuuAndEd := "\x1b[%dA\x1b[J"
+	for i := 0; i < b.N; i++ {
+		fmt.Fprintf(ioutil.Discard, cuuAndEd, 4)
+	}
+}
+
+func BenchmarkWithJoin(b *testing.B) {
+	bCuuAndEd := [][]byte{[]byte("\x1b["), []byte("A\x1b[J")}
+	for i := 0; i < b.N; i++ {
+		ioutil.Discard.Write(bytes.Join(bCuuAndEd, []byte(strconv.Itoa(4))))
+	}
+}
+
+func BenchmarkWithAppend(b *testing.B) {
+	escOpen := []byte("\x1b[")
+	cuuAndEd := []byte("A\x1b[J")
+	for i := 0; i < b.N; i++ {
+		ioutil.Discard.Write(append(strconv.AppendInt(escOpen, 4, 10), cuuAndEd...))
+	}
+}
+
+func BenchmarkWithCopy(b *testing.B) {
+	w := New(ioutil.Discard)
+	w.lineCount = 4
+	for i := 0; i < b.N; i++ {
+		w.ansiCuuAndEd()
+	}
+}
diff --git a/cwriter/writer.go b/cwriter/writer.go
index 80a167f..c068877 100644
--- a/cwriter/writer.go
+++ b/cwriter/writer.go
@@ -5,6 +5,7 @@
 	"errors"
 	"io"
 	"os"
+	"strconv"
 
 	"github.com/mattn/go-isatty"
 )
@@ -12,7 +13,11 @@
 // NotATTY not a TeleTYpewriter error.
 var NotATTY = errors.New("not a terminal")
 
-const cuuAndEd = "\x1b[%dA\x1b[J"
+// http://ascii-table.com/ansi-escape-sequences.php
+const (
+	escOpen  = "\x1b["
+	cuuAndEd = "A\x1b[J"
+)
 
 // Writer is a buffered the writer that updates the terminal. The
 // contents of writer will be flushed when Flush is called.
@@ -69,3 +74,9 @@
 	tw, _, err := GetSize(w.fd)
 	return tw, err
 }
+
+func (w *Writer) ansiCuuAndEd() {
+	buf := make([]byte, 8)
+	buf = strconv.AppendInt(buf[:copy(buf, escOpen)], int64(w.lineCount), 10)
+	w.out.Write(append(buf, cuuAndEd...))
+}
diff --git a/cwriter/writer_posix.go b/cwriter/writer_posix.go
index e836cec..7c7947b 100644
--- a/cwriter/writer_posix.go
+++ b/cwriter/writer_posix.go
@@ -3,13 +3,11 @@
 package cwriter
 
 import (
-	"fmt"
-
 	"golang.org/x/sys/unix"
 )
 
 func (w *Writer) clearLines() {
-	fmt.Fprintf(w.out, cuuAndEd, w.lineCount)
+	w.ansiCuuAndEd()
 }
 
 // GetSize returns the dimensions of the given terminal.
diff --git a/cwriter/writer_windows.go b/cwriter/writer_windows.go
index 7a3ed5b..71bb30c 100644
--- a/cwriter/writer_windows.go
+++ b/cwriter/writer_windows.go
@@ -3,9 +3,10 @@
 package cwriter
 
 import (
-	"fmt"
 	"syscall"
 	"unsafe"
+
+	"github.com/mattn/go-isatty"
 )
 
 var kernel32 = syscall.NewLazyDLL("kernel32.dll")
@@ -37,8 +38,8 @@
 }
 
 func (w *Writer) clearLines() {
-	if !w.isTerminal {
-		fmt.Fprintf(w.out, cuuAndEd, w.lineCount)
+	if !w.isTerminal && isatty.IsCygwinTerminal(w.fd) {
+		w.ansiCuuAndEd()
 	}
 
 	info := new(consoleScreenBufferInfo)