diff --git a/output.go b/output.go
index e22d369..2b692e8 100644
--- a/output.go
+++ b/output.go
@@ -23,7 +23,7 @@ type OutputOption = func(*Output)
 // Output is a terminal output.
 type Output struct {
 	Profile
-	tty     io.Writer
+	w       io.Writer
 	environ Environ
 
 	assumeTTY bool
@@ -61,10 +61,10 @@ func SetDefaultOutput(o *Output) {
 	output = o
 }
 
-// NewOutput returns a new Output for the given file descriptor.
-func NewOutput(tty io.Writer, opts ...OutputOption) *Output {
+// NewOutput returns a new Output for the given writer.
+func NewOutput(w io.Writer, opts ...OutputOption) *Output {
 	o := &Output{
-		tty:     tty,
+		w:       w,
 		environ: &osEnviron{},
 		Profile: -1,
 		fgSync:  &sync.Once{},
@@ -73,8 +73,8 @@ func NewOutput(tty io.Writer, opts ...OutputOption) *Output {
 		bgColor: NoColor{},
 	}
 
-	if o.tty == nil {
-		o.tty = os.Stdout
+	if o.w == nil {
+		o.w = os.Stdout
 	}
 	for _, opt := range opts {
 		opt(o)
@@ -180,15 +180,23 @@ func (o *Output) HasDarkBackground() bool {
 
 // TTY returns the terminal's file descriptor. This may be nil if the output is
 // not a terminal.
+//
+// Deprecated: Use Writer() instead.
 func (o Output) TTY() File {
-	if f, ok := o.tty.(File); ok {
+	if f, ok := o.w.(File); ok {
 		return f
 	}
 	return nil
 }
 
+// Writer returns the underlying writer. This may be of type io.Writer,
+// io.ReadWriter, or *os.File.
+func (o Output) Writer() io.Writer {
+	return o.w
+}
+
 func (o Output) Write(p []byte) (int, error) {
-	return o.tty.Write(p)
+	return o.w.Write(p)
 }
 
 // WriteString writes the given string to the output.
diff --git a/screen.go b/screen.go
index a71181b..19f28dc 100644
--- a/screen.go
+++ b/screen.go
@@ -71,234 +71,234 @@ const (
 
 // Reset the terminal to its default style, removing any active styles.
 func (o Output) Reset() {
-	fmt.Fprint(o.tty, CSI+ResetSeq+"m")
+	fmt.Fprint(o.w, CSI+ResetSeq+"m")
 }
 
 // SetForegroundColor sets the default foreground color.
 func (o Output) SetForegroundColor(color Color) {
-	fmt.Fprintf(o.tty, OSC+SetForegroundColorSeq, color)
+	fmt.Fprintf(o.w, OSC+SetForegroundColorSeq, color)
 }
 
 // SetBackgroundColor sets the default background color.
 func (o Output) SetBackgroundColor(color Color) {
-	fmt.Fprintf(o.tty, OSC+SetBackgroundColorSeq, color)
+	fmt.Fprintf(o.w, OSC+SetBackgroundColorSeq, color)
 }
 
 // SetCursorColor sets the cursor color.
 func (o Output) SetCursorColor(color Color) {
-	fmt.Fprintf(o.tty, OSC+SetCursorColorSeq, color)
+	fmt.Fprintf(o.w, OSC+SetCursorColorSeq, color)
 }
 
 // RestoreScreen restores a previously saved screen state.
 func (o Output) RestoreScreen() {
-	fmt.Fprint(o.tty, CSI+RestoreScreenSeq)
+	fmt.Fprint(o.w, CSI+RestoreScreenSeq)
 }
 
 // SaveScreen saves the screen state.
 func (o Output) SaveScreen() {
-	fmt.Fprint(o.tty, CSI+SaveScreenSeq)
+	fmt.Fprint(o.w, CSI+SaveScreenSeq)
 }
 
 // AltScreen switches to the alternate screen buffer. The former view can be
 // restored with ExitAltScreen().
 func (o Output) AltScreen() {
-	fmt.Fprint(o.tty, CSI+AltScreenSeq)
+	fmt.Fprint(o.w, CSI+AltScreenSeq)
 }
 
 // ExitAltScreen exits the alternate screen buffer and returns to the former
 // terminal view.
 func (o Output) ExitAltScreen() {
-	fmt.Fprint(o.tty, CSI+ExitAltScreenSeq)
+	fmt.Fprint(o.w, CSI+ExitAltScreenSeq)
 }
 
 // ClearScreen clears the visible portion of the terminal.
 func (o Output) ClearScreen() {
-	fmt.Fprintf(o.tty, CSI+EraseDisplaySeq, 2)
+	fmt.Fprintf(o.w, CSI+EraseDisplaySeq, 2)
 	o.MoveCursor(1, 1)
 }
 
 // MoveCursor moves the cursor to a given position.
 func (o Output) MoveCursor(row int, column int) {
-	fmt.Fprintf(o.tty, CSI+CursorPositionSeq, row, column)
+	fmt.Fprintf(o.w, CSI+CursorPositionSeq, row, column)
 }
 
 // HideCursor hides the cursor.
 func (o Output) HideCursor() {
-	fmt.Fprint(o.tty, CSI+HideCursorSeq)
+	fmt.Fprint(o.w, CSI+HideCursorSeq)
 }
 
 // ShowCursor shows the cursor.
 func (o Output) ShowCursor() {
-	fmt.Fprint(o.tty, CSI+ShowCursorSeq)
+	fmt.Fprint(o.w, CSI+ShowCursorSeq)
 }
 
 // SaveCursorPosition saves the cursor position.
 func (o Output) SaveCursorPosition() {
-	fmt.Fprint(o.tty, CSI+SaveCursorPositionSeq)
+	fmt.Fprint(o.w, CSI+SaveCursorPositionSeq)
 }
 
 // RestoreCursorPosition restores a saved cursor position.
 func (o Output) RestoreCursorPosition() {
-	fmt.Fprint(o.tty, CSI+RestoreCursorPositionSeq)
+	fmt.Fprint(o.w, CSI+RestoreCursorPositionSeq)
 }
 
 // CursorUp moves the cursor up a given number of lines.
 func (o Output) CursorUp(n int) {
-	fmt.Fprintf(o.tty, CSI+CursorUpSeq, n)
+	fmt.Fprintf(o.w, CSI+CursorUpSeq, n)
 }
 
 // CursorDown moves the cursor down a given number of lines.
 func (o Output) CursorDown(n int) {
-	fmt.Fprintf(o.tty, CSI+CursorDownSeq, n)
+	fmt.Fprintf(o.w, CSI+CursorDownSeq, n)
 }
 
 // CursorForward moves the cursor up a given number of lines.
 func (o Output) CursorForward(n int) {
-	fmt.Fprintf(o.tty, CSI+CursorForwardSeq, n)
+	fmt.Fprintf(o.w, CSI+CursorForwardSeq, n)
 }
 
 // CursorBack moves the cursor backwards a given number of cells.
 func (o Output) CursorBack(n int) {
-	fmt.Fprintf(o.tty, CSI+CursorBackSeq, n)
+	fmt.Fprintf(o.w, CSI+CursorBackSeq, n)
 }
 
 // CursorNextLine moves the cursor down a given number of lines and places it at
 // the beginning of the line.
 func (o Output) CursorNextLine(n int) {
-	fmt.Fprintf(o.tty, CSI+CursorNextLineSeq, n)
+	fmt.Fprintf(o.w, CSI+CursorNextLineSeq, n)
 }
 
 // CursorPrevLine moves the cursor up a given number of lines and places it at
 // the beginning of the line.
 func (o Output) CursorPrevLine(n int) {
-	fmt.Fprintf(o.tty, CSI+CursorPreviousLineSeq, n)
+	fmt.Fprintf(o.w, CSI+CursorPreviousLineSeq, n)
 }
 
 // ClearLine clears the current line.
 func (o Output) ClearLine() {
-	fmt.Fprint(o.tty, CSI+EraseEntireLineSeq)
+	fmt.Fprint(o.w, CSI+EraseEntireLineSeq)
 }
 
 // ClearLineLeft clears the line to the left of the cursor.
 func (o Output) ClearLineLeft() {
-	fmt.Fprint(o.tty, CSI+EraseLineLeftSeq)
+	fmt.Fprint(o.w, CSI+EraseLineLeftSeq)
 }
 
 // ClearLineRight clears the line to the right of the cursor.
 func (o Output) ClearLineRight() {
-	fmt.Fprint(o.tty, CSI+EraseLineRightSeq)
+	fmt.Fprint(o.w, CSI+EraseLineRightSeq)
 }
 
 // ClearLines clears a given number of lines.
 func (o Output) ClearLines(n int) {
 	clearLine := fmt.Sprintf(CSI+EraseLineSeq, 2)
 	cursorUp := fmt.Sprintf(CSI+CursorUpSeq, 1)
-	fmt.Fprint(o.tty, clearLine+strings.Repeat(cursorUp+clearLine, n))
+	fmt.Fprint(o.w, clearLine+strings.Repeat(cursorUp+clearLine, n))
 }
 
 // ChangeScrollingRegion sets the scrolling region of the terminal.
 func (o Output) ChangeScrollingRegion(top, bottom int) {
-	fmt.Fprintf(o.tty, CSI+ChangeScrollingRegionSeq, top, bottom)
+	fmt.Fprintf(o.w, CSI+ChangeScrollingRegionSeq, top, bottom)
 }
 
 // InsertLines inserts the given number of lines at the top of the scrollable
 // region, pushing lines below down.
 func (o Output) InsertLines(n int) {
-	fmt.Fprintf(o.tty, CSI+InsertLineSeq, n)
+	fmt.Fprintf(o.w, CSI+InsertLineSeq, n)
 }
 
 // DeleteLines deletes the given number of lines, pulling any lines in
 // the scrollable region below up.
 func (o Output) DeleteLines(n int) {
-	fmt.Fprintf(o.tty, CSI+DeleteLineSeq, n)
+	fmt.Fprintf(o.w, CSI+DeleteLineSeq, n)
 }
 
 // EnableMousePress enables X10 mouse mode. Button press events are sent only.
 func (o Output) EnableMousePress() {
-	fmt.Fprint(o.tty, CSI+EnableMousePressSeq)
+	fmt.Fprint(o.w, CSI+EnableMousePressSeq)
 }
 
 // DisableMousePress disables X10 mouse mode.
 func (o Output) DisableMousePress() {
-	fmt.Fprint(o.tty, CSI+DisableMousePressSeq)
+	fmt.Fprint(o.w, CSI+DisableMousePressSeq)
 }
 
 // EnableMouse enables Mouse Tracking mode.
 func (o Output) EnableMouse() {
-	fmt.Fprint(o.tty, CSI+EnableMouseSeq)
+	fmt.Fprint(o.w, CSI+EnableMouseSeq)
 }
 
 // DisableMouse disables Mouse Tracking mode.
 func (o Output) DisableMouse() {
-	fmt.Fprint(o.tty, CSI+DisableMouseSeq)
+	fmt.Fprint(o.w, CSI+DisableMouseSeq)
 }
 
 // EnableMouseHilite enables Hilite Mouse Tracking mode.
 func (o Output) EnableMouseHilite() {
-	fmt.Fprint(o.tty, CSI+EnableMouseHiliteSeq)
+	fmt.Fprint(o.w, CSI+EnableMouseHiliteSeq)
 }
 
 // DisableMouseHilite disables Hilite Mouse Tracking mode.
 func (o Output) DisableMouseHilite() {
-	fmt.Fprint(o.tty, CSI+DisableMouseHiliteSeq)
+	fmt.Fprint(o.w, CSI+DisableMouseHiliteSeq)
 }
 
 // EnableMouseCellMotion enables Cell Motion Mouse Tracking mode.
 func (o Output) EnableMouseCellMotion() {
-	fmt.Fprint(o.tty, CSI+EnableMouseCellMotionSeq)
+	fmt.Fprint(o.w, CSI+EnableMouseCellMotionSeq)
 }
 
 // DisableMouseCellMotion disables Cell Motion Mouse Tracking mode.
 func (o Output) DisableMouseCellMotion() {
-	fmt.Fprint(o.tty, CSI+DisableMouseCellMotionSeq)
+	fmt.Fprint(o.w, CSI+DisableMouseCellMotionSeq)
 }
 
 // EnableMouseAllMotion enables All Motion Mouse mode.
 func (o Output) EnableMouseAllMotion() {
-	fmt.Fprint(o.tty, CSI+EnableMouseAllMotionSeq)
+	fmt.Fprint(o.w, CSI+EnableMouseAllMotionSeq)
 }
 
 // DisableMouseAllMotion disables All Motion Mouse mode.
 func (o Output) DisableMouseAllMotion() {
-	fmt.Fprint(o.tty, CSI+DisableMouseAllMotionSeq)
+	fmt.Fprint(o.w, CSI+DisableMouseAllMotionSeq)
 }
 
 // EnableMouseExtendedMotion enables Extended Mouse mode (SGR). This should be
 // enabled in conjunction with EnableMouseCellMotion, and EnableMouseAllMotion.
 func (o Output) EnableMouseExtendedMode() {
-	fmt.Fprint(o.tty, CSI+EnableMouseExtendedModeSeq)
+	fmt.Fprint(o.w, CSI+EnableMouseExtendedModeSeq)
 }
 
 // DisableMouseExtendedMotion disables Extended Mouse mode (SGR).
 func (o Output) DisableMouseExtendedMode() {
-	fmt.Fprint(o.tty, CSI+DisableMouseExtendedModeSeq)
+	fmt.Fprint(o.w, CSI+DisableMouseExtendedModeSeq)
 }
 
 // EnableMousePixelsMotion enables Pixel Motion Mouse mode (SGR-Pixels). This
 // should be enabled in conjunction with EnableMouseCellMotion, and
 // EnableMouseAllMotion.
 func (o Output) EnableMousePixelsMode() {
-	fmt.Fprint(o.tty, CSI+EnableMousePixelsModeSeq)
+	fmt.Fprint(o.w, CSI+EnableMousePixelsModeSeq)
 }
 
 // DisableMousePixelsMotion disables Pixel Motion Mouse mode (SGR-Pixels).
 func (o Output) DisableMousePixelsMode() {
-	fmt.Fprint(o.tty, CSI+DisableMousePixelsModeSeq)
+	fmt.Fprint(o.w, CSI+DisableMousePixelsModeSeq)
 }
 
 // SetWindowTitle sets the terminal window title.
 func (o Output) SetWindowTitle(title string) {
-	fmt.Fprintf(o.tty, OSC+SetWindowTitleSeq, title)
+	fmt.Fprintf(o.w, OSC+SetWindowTitleSeq, title)
 }
 
 // EnableBracketedPaste enables bracketed paste.
 func (o Output) EnableBracketedPaste() {
-	fmt.Fprintf(o.tty, CSI+EnableBracketedPasteSeq)
+	fmt.Fprintf(o.w, CSI+EnableBracketedPasteSeq)
 }
 
 // DisableBracketedPaste disables bracketed paste.
 func (o Output) DisableBracketedPaste() {
-	fmt.Fprintf(o.tty, CSI+DisableBracketedPasteSeq)
+	fmt.Fprintf(o.w, CSI+DisableBracketedPasteSeq)
 }
 
 // Legacy functions.
diff --git a/screen_test.go b/screen_test.go
index aa40595..7e2a845 100644
--- a/screen_test.go
+++ b/screen_test.go
@@ -34,7 +34,7 @@ func tempOutput(t *testing.T) *Output {
 
 func verify(t *testing.T, o *Output, exp string) {
 	t.Helper()
-	tty := o.tty.(*os.File)
+	tty := o.w.(*os.File)
 
 	if _, err := tty.Seek(0, 0); err != nil {
 		t.Fatal(err)
diff --git a/termenv.go b/termenv.go
index 4ceb271..84a82c2 100644
--- a/termenv.go
+++ b/termenv.go
@@ -2,6 +2,7 @@ package termenv
 
 import (
 	"errors"
+	"os"
 
 	"github.com/mattn/go-isatty"
 )
@@ -31,11 +32,11 @@ func (o *Output) isTTY() bool {
 	if len(o.environ.Getenv("CI")) > 0 {
 		return false
 	}
-	if o.TTY() == nil {
-		return false
+	if f, ok := o.Writer().(*os.File); ok {
+		return isatty.IsTerminal(f.Fd())
 	}
 
-	return isatty.IsTerminal(o.TTY().Fd())
+	return false
 }
 
 // ColorProfile returns the supported color profile:
diff --git a/termenv_windows.go b/termenv_windows.go
index 1d9c618..f9b1def 100644
--- a/termenv_windows.go
+++ b/termenv_windows.go
@@ -5,6 +5,7 @@ package termenv
 
 import (
 	"fmt"
+	"os"
 	"strconv"
 
 	"golang.org/x/sys/windows"
@@ -103,8 +104,8 @@ func EnableVirtualTerminalProcessing(o *Output) (restoreFunc func() error, err e
 	}
 
 	// If o is not a tty, then there is nothing to do.
-	tty := o.TTY()
-	if tty == nil {
+	tty, ok := o.Writer().(*os.File)
+	if tty == nil || !ok {
 		return
 	}