diff --git a/cwriter/writer.go b/cwriter/writer.go
index fac15b3..ee717df 100644
--- a/cwriter/writer.go
+++ b/cwriter/writer.go
@@ -20,19 +20,32 @@
 // Writer is a buffered the writer that updates the terminal. The
 // contents of writer will be flushed when Flush is called.
 type Writer struct {
-	out        io.Writer
-	buf        bytes.Buffer
-	lines      int
-	fd         int
-	isTerminal bool
+	out      io.Writer
+	buf      bytes.Buffer
+	lines    int // how much lines to clear before flushing new ones
+	termSize func() (int, int, error)
+}
+
+func prepareTermSizeFunc(out io.Writer) func() (int, int, error) {
+	fn := func() (int, int, error) {
+		return -1, -1, ErrNotTTY
+	}
+	if f, ok := out.(*os.File); ok {
+		fd := int(f.Fd())
+		if IsTerminal(fd) {
+			fn = func() (int, int, error) {
+				return GetSize(fd)
+			}
+		}
+	}
+	return fn
 }
 
 // New returns a new Writer with defaults.
 func New(out io.Writer) *Writer {
-	w := &Writer{out: out}
-	if f, ok := out.(*os.File); ok {
-		w.fd = int(f.Fd())
-		w.isTerminal = IsTerminal(w.fd)
+	w := &Writer{
+		out:      out,
+		termSize: prepareTermSizeFunc(out),
 	}
 	return w
 }
@@ -67,13 +80,9 @@
 	return w.buf.ReadFrom(r)
 }
 
-// GetWidth returns width of underlying terminal.
-func (w *Writer) GetWidth() (int, error) {
-	if !w.isTerminal {
-		return -1, ErrNotTTY
-	}
-	tw, _, err := GetSize(w.fd)
-	return tw, err
+// GetTermSize returns WxH of underlying terminal.
+func (w *Writer) GetTermSize() (width, height int, err error) {
+	return w.termSize()
 }
 
 func (w *Writer) ansiCuuAndEd() error {