diff --git a/browser.go b/browser.go
index d7969d7..89a07bf 100644
--- a/browser.go
+++ b/browser.go
@@ -18,18 +18,50 @@ var Stdout io.Writer = os.Stdout
 // Stderr is the io.Writer to which executed commands write standard error.
 var Stderr io.Writer = os.Stderr
 
+// Opener allows customizing browser opening behavior.
+type Opener struct {
+	// Stdout is the io.Writer to which executed commands write standard output.
+	// If nil, os.Stdout is used.
+	Stdout io.Writer
+
+	// Stderr is the io.Writer to which executed commands write standard error.
+	// If nil, os.Stderr is used.
+	Stderr io.Writer
+}
+
+func (o *Opener) stdout() io.Writer {
+	if o.Stdout != nil {
+		return o.Stdout
+	}
+	return Stdout
+}
+
+func (o *Opener) stderr() io.Writer {
+	if o.Stderr != nil {
+		return o.Stderr
+	}
+	return Stderr
+}
+
+func (o *Opener) runCmd(prog string, args ...string) error {
+	cmd := exec.Command(prog, args...)
+	cmd.Stdout = o.stdout()
+	cmd.Stderr = o.stderr()
+	return cmd.Run()
+}
+
 // OpenFile opens new browser window for the file path.
-func OpenFile(path string) error {
+func (o *Opener) OpenFile(path string) error {
 	path, err := filepath.Abs(path)
 	if err != nil {
 		return err
 	}
-	return OpenURL("file://" + path)
+	return o.OpenURL("file://" + path)
 }
 
 // OpenReader consumes the contents of r and presents the
 // results in a new browser window.
-func OpenReader(r io.Reader) error {
+func (o *Opener) OpenReader(r io.Reader) error {
 	f, err := ioutil.TempFile("", "browser.*.html")
 	if err != nil {
 		return fmt.Errorf("browser: could not create temporary file: %v", err)
@@ -41,17 +73,35 @@ func OpenReader(r io.Reader) error {
 	if err := f.Close(); err != nil {
 		return fmt.Errorf("browser: caching temporary file failed: %v", err)
 	}
-	return OpenFile(f.Name())
+	return o.OpenFile(f.Name())
 }
 
 // OpenURL opens a new browser window pointing to url.
-func OpenURL(url string) error {
-	return openBrowser(url)
+func (o *Opener) OpenURL(url string) error {
+	return o.openBrowser(url)
 }
 
-func runCmd(prog string, args ...string) error {
-	cmd := exec.Command(prog, args...)
-	cmd.Stdout = Stdout
-	cmd.Stderr = Stderr
-	return cmd.Run()
+// defaultOpener returns an Opener configured with the package-level Stdout/Stderr.
+// This is done as a function to always grab the latest values of Stdout/Stderr.
+func defaultOpener() *Opener {
+	return &Opener{
+		Stdout: Stdout,
+		Stderr: Stderr,
+	}
+}
+
+// OpenFile opens new browser window for the file path.
+func OpenFile(path string) error {
+	return defaultOpener().OpenFile(path)
+}
+
+// OpenReader consumes the contents of r and presents the
+// results in a new browser window.
+func OpenReader(r io.Reader) error {
+	return defaultOpener().OpenReader(r)
+}
+
+// OpenURL opens a new browser window pointing to url.
+func OpenURL(url string) error {
+	return defaultOpener().OpenURL(url)
 }
diff --git a/browser_darwin.go b/browser_darwin.go
index 8507cf7..2ea95f2 100644
--- a/browser_darwin.go
+++ b/browser_darwin.go
@@ -1,5 +1,5 @@
 package browser
 
-func openBrowser(url string) error {
-	return runCmd("open", url)
+func (o *Opener) openBrowser(url string) error {
+	return o.runCmd("open", url)
 }
diff --git a/browser_freebsd.go b/browser_freebsd.go
index 4fc7ff0..48b7f62 100644
--- a/browser_freebsd.go
+++ b/browser_freebsd.go
@@ -5,8 +5,8 @@ import (
 	"os/exec"
 )
 
-func openBrowser(url string) error {
-	err := runCmd("xdg-open", url)
+func (o *Opener) openBrowser(url string) error {
+	err := o.runCmd("xdg-open", url)
 	if e, ok := err.(*exec.Error); ok && e.Err == exec.ErrNotFound {
 		return errors.New("xdg-open: command not found - install xdg-utils from ports(8)")
 	}
diff --git a/browser_linux.go b/browser_linux.go
index d26cddd..42f3b6f 100644
--- a/browser_linux.go
+++ b/browser_linux.go
@@ -5,7 +5,7 @@ import (
 	"strings"
 )
 
-func openBrowser(url string) error {
+func (o *Opener) openBrowser(url string) error {
 	providers := []string{"xdg-open", "x-www-browser", "www-browser"}
 
 	// There are multiple possible providers to open a browser on linux
@@ -13,7 +13,7 @@ func openBrowser(url string) error {
 	// Look for one that exists and run it
 	for _, provider := range providers {
 		if _, err := exec.LookPath(provider); err == nil {
-			return runCmd(provider, url)
+			return o.runCmd(provider, url)
 		}
 	}
 
diff --git a/browser_netbsd.go b/browser_netbsd.go
index 65a5e5a..db5c9a9 100644
--- a/browser_netbsd.go
+++ b/browser_netbsd.go
@@ -5,8 +5,8 @@ import (
 	"os/exec"
 )
 
-func openBrowser(url string) error {
-	err := runCmd("xdg-open", url)
+func (o *Opener) openBrowser(url string) error {
+	err := o.runCmd("xdg-open", url)
 	if e, ok := err.(*exec.Error); ok && e.Err == exec.ErrNotFound {
 		return errors.New("xdg-open: command not found - install xdg-utils from pkgsrc(7)")
 	}
diff --git a/browser_openbsd.go b/browser_openbsd.go
index 4fc7ff0..48b7f62 100644
--- a/browser_openbsd.go
+++ b/browser_openbsd.go
@@ -5,8 +5,8 @@ import (
 	"os/exec"
 )
 
-func openBrowser(url string) error {
-	err := runCmd("xdg-open", url)
+func (o *Opener) openBrowser(url string) error {
+	err := o.runCmd("xdg-open", url)
 	if e, ok := err.(*exec.Error); ok && e.Err == exec.ErrNotFound {
 		return errors.New("xdg-open: command not found - install xdg-utils from ports(8)")
 	}
diff --git a/browser_test.go b/browser_test.go
new file mode 100644
index 0000000..6ffbadf
--- /dev/null
+++ b/browser_test.go
@@ -0,0 +1,19 @@
+package browser
+
+import (
+	"bytes"
+	"path/filepath"
+	"testing"
+)
+
+func TestErrorRedirect(t *testing.T) {
+	stderr := new(bytes.Buffer)
+	o := &Opener{
+		Stderr: stderr,
+	}
+
+	_ = o.OpenFile(filepath.Join(t.TempDir(), "nonexistentfile.html"))
+	if stderr.Len() == 0 {
+		t.Errorf("expected stderr to contain error message, got empty")
+	}
+}
diff --git a/browser_unsupported.go b/browser_unsupported.go
index 7c5c17d..29d9a9f 100644
--- a/browser_unsupported.go
+++ b/browser_unsupported.go
@@ -1,3 +1,4 @@
+//go:build !linux && !windows && !darwin && !openbsd && !freebsd && !netbsd
 // +build !linux,!windows,!darwin,!openbsd,!freebsd,!netbsd
 
 package browser
@@ -7,6 +8,6 @@ import (
 	"runtime"
 )
 
-func openBrowser(url string) error {
+func (o *Opener) openBrowser(url string) error {
 	return fmt.Errorf("openBrowser: unsupported operating system: %v", runtime.GOOS)
 }
diff --git a/browser_windows.go b/browser_windows.go
index 63e1929..eac213f 100644
--- a/browser_windows.go
+++ b/browser_windows.go
@@ -2,6 +2,6 @@ package browser
 
 import "golang.org/x/sys/windows"
 
-func openBrowser(url string) error {
+func (o *Opener) openBrowser(url string) error {
 	return windows.ShellExecute(0, nil, windows.StringToUTF16Ptr(url), nil, nil, windows.SW_SHOWNORMAL)
 }