diff --git a/logger.go b/logger.go
index 3ebdaea..ce7edd1 100644
--- a/logger.go
+++ b/logger.go
@@ -57,23 +57,7 @@ func (l Level) String() string {
 // Field is a context field.
 type Field func(*Event)
 
-// Logger represents a log writer.
-type Logger interface {
-	// With returns a logger with context.
-	With(ctx ...Field) Logger
-	// Debug logs a debug message.
-	Debug(msg string, ctx ...Field)
-	// Info logs an informational message.
-	Info(msg string, ctx ...Field)
-	// Warn logs a warning message.
-	Warn(msg string, ctx ...Field)
-	// Error logs an error message.
-	Error(msg string, ctx ...Field)
-	// Crit logs a critical message.
-	Crit(msg string, ctx ...Field)
-}
-
-type logger struct {
+type Logger struct {
 	w    io.Writer
 	fmtr Formatter
 	lvl  Level
@@ -81,16 +65,16 @@ type logger struct {
 }
 
 // New creates a new Logger.
-func New(w io.Writer, fmtr Formatter, lvl Level) Logger {
-	return &logger{
+func New(w io.Writer, fmtr Formatter, lvl Level) *Logger {
+	return &Logger{
 		w:    w,
 		fmtr: fmtr,
 		lvl:  lvl,
 	}
 }
 
-// With returns a new logger with the given context.
-func (l *logger) With(ctx ...Field) Logger {
+// With returns a new Logger with the given context.
+func (l *Logger) With(ctx ...Field) *Logger {
 	e := newEvent(l.fmtr)
 	defer putEvent(e)
 
@@ -103,7 +87,7 @@ func (l *logger) With(ctx ...Field) Logger {
 	b := make([]byte, e.buf.Len())
 	copy(b, e.buf.Bytes())
 
-	return &logger{
+	return &Logger{
 		w:    l.w,
 		fmtr: l.fmtr,
 		lvl:  l.lvl,
@@ -112,31 +96,31 @@ func (l *logger) With(ctx ...Field) Logger {
 }
 
 // Debug logs a debug message.
-func (l *logger) Debug(msg string, ctx ...Field) {
+func (l *Logger) Debug(msg string, ctx ...Field) {
 	l.write(msg, Debug, ctx)
 }
 
 // Info logs an informational message.
-func (l *logger) Info(msg string, ctx ...Field) {
+func (l *Logger) Info(msg string, ctx ...Field) {
 	l.write(msg, Info, ctx)
 }
 
 // Warn logs a warning message.
-func (l *logger) Warn(msg string, ctx ...Field) {
+func (l *Logger) Warn(msg string, ctx ...Field) {
 	l.write(msg, Warn, ctx)
 }
 
 // Error logs an error message.
-func (l *logger) Error(msg string, ctx ...Field) {
+func (l *Logger) Error(msg string, ctx ...Field) {
 	l.write(msg, Error, ctx)
 }
 
 // Crit logs a critical message.
-func (l *logger) Crit(msg string, ctx ...Field) {
+func (l *Logger) Crit(msg string, ctx ...Field) {
 	l.write(msg, Crit, ctx)
 }
 
-func (l *logger) write(msg string, lvl Level, ctx []Field) {
+func (l *Logger) write(msg string, lvl Level, ctx []Field) {
 	if lvl > l.lvl {
 		return
 	}
diff --git a/logger_test.go b/logger_test.go
index cabc6f1..0ed99ec 100644
--- a/logger_test.go
+++ b/logger_test.go
@@ -114,38 +114,38 @@ func TestLevel_String(t *testing.T) {
 func TestNew(t *testing.T) {
 	log := logger.New(io.Discard, logger.LogfmtFormat(), logger.Debug)
 
-	assert.Implements(t, (*logger.Logger)(nil), log)
+	assert.IsType(t, &logger.Logger{}, log)
 }
 
 func TestLogger(t *testing.T) {
 	tests := []struct {
 		name string
-		fn   func(l logger.Logger)
+		fn   func(l *logger.Logger)
 		want string
 	}{
 		{
 			name: "Debug",
-			fn:   func(l logger.Logger) { l.Debug("debug", ctx.Str("level", "debug")) },
+			fn:   func(l *logger.Logger) { l.Debug("debug", ctx.Str("level", "debug")) },
 			want: "lvl=dbug msg=debug level=debug\n",
 		},
 		{
 			name: "Info",
-			fn:   func(l logger.Logger) { l.Info("info", ctx.Str("level", "info")) },
+			fn:   func(l *logger.Logger) { l.Info("info", ctx.Str("level", "info")) },
 			want: "lvl=info msg=info level=info\n",
 		},
 		{
 			name: "Warn",
-			fn:   func(l logger.Logger) { l.Warn("warn", ctx.Str("level", "warn")) },
+			fn:   func(l *logger.Logger) { l.Warn("warn", ctx.Str("level", "warn")) },
 			want: "lvl=warn msg=warn level=warn\n",
 		},
 		{
 			name: "Error",
-			fn:   func(l logger.Logger) { l.Error("error", ctx.Str("level", "error")) },
+			fn:   func(l *logger.Logger) { l.Error("error", ctx.Str("level", "error")) },
 			want: "lvl=eror msg=error level=error\n",
 		},
 		{
 			name: "Crit",
-			fn:   func(l logger.Logger) { l.Crit("critical", ctx.Str("level", "critical")) },
+			fn:   func(l *logger.Logger) { l.Crit("critical", ctx.Str("level", "critical")) },
 			want: "lvl=crit msg=critical level=critical\n",
 		},
 	}