diff --git a/src/go/build/deps_test.go b/src/go/build/deps_test.go
index 8779b8b8c1..a287eeda67 100644
--- a/src/go/build/deps_test.go
+++ b/src/go/build/deps_test.go
@@ -45,6 +45,7 @@ var depsRules = `
 	  internal/cpu, internal/goarch,
 	  internal/goexperiment, internal/goos,
 	  internal/goversion, internal/nettrace, internal/platform,
+	  log/internal,
 	  maps, slices, unicode/utf8, unicode/utf16, unicode,
 	  unsafe;
 
@@ -369,7 +370,7 @@ var depsRules = `
 	< NET;
 
 	# logging - most packages should not import; http and up is allowed
-	FMT
+	FMT, log/internal
 	< log;
 
 	log, log/slog !< crypto/tls, database/sql, go/importer, testing;
@@ -382,7 +383,7 @@ var depsRules = `
 
 	FMT,
 	encoding, encoding/json,
-	log,
+	log, log/internal,
 	log/slog/internal, log/slog/internal/buffer,
 	slices
 	< log/slog
diff --git a/src/log/internal/internal.go b/src/log/internal/internal.go
new file mode 100644
index 0000000000..d5af2c536c
--- /dev/null
+++ b/src/log/internal/internal.go
@@ -0,0 +1,12 @@
+// Copyright 2023 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package internal contains definitions used by both log and log/slog.
+package internal
+
+// DefaultOutput holds a function which calls the default log.Logger's
+// output function.
+// It allows slog.defaultHandler to call into an unexported function of
+// the log package.
+var DefaultOutput func(pc uintptr, data []byte) error
diff --git a/src/log/log.go b/src/log/log.go
index c02a98be49..9d5440ea3a 100644
--- a/src/log/log.go
+++ b/src/log/log.go
@@ -17,6 +17,7 @@ package log
 import (
 	"fmt"
 	"io"
+	"log/internal"
 	"os"
 	"runtime"
 	"sync"
@@ -191,12 +192,14 @@ func putBuffer(p *[]byte) {
 // paths it will be 2.
 func (l *Logger) Output(calldepth int, s string) error {
 	calldepth++ // +1 for this frame.
-	return l.output(calldepth, func(b []byte) []byte {
+	return l.output(0, calldepth, func(b []byte) []byte {
 		return append(b, s...)
 	})
 }
 
-func (l *Logger) output(calldepth int, appendOutput func([]byte) []byte) error {
+// output can take either a calldepth or a pc to get source line information.
+// It uses the pc if it is non-zero.
+func (l *Logger) output(pc uintptr, calldepth int, appendOutput func([]byte) []byte) error {
 	if l.isDiscard.Load() {
 		return nil
 	}
@@ -211,11 +214,21 @@ func (l *Logger) output(calldepth int, appendOutput func([]byte) []byte) error {
 	var file string
 	var line int
 	if flag&(Lshortfile|Llongfile) != 0 {
-		var ok bool
-		_, file, line, ok = runtime.Caller(calldepth)
-		if !ok {
-			file = "???"
-			line = 0
+		if pc == 0 {
+			var ok bool
+			_, file, line, ok = runtime.Caller(calldepth)
+			if !ok {
+				file = "???"
+				line = 0
+			}
+		} else {
+			fs := runtime.CallersFrames([]uintptr{pc})
+			f, _ := fs.Next()
+			file = f.File
+			if file == "" {
+				file = "???"
+			}
+			line = f.Line
 		}
 	}
 
@@ -233,10 +246,18 @@ func (l *Logger) output(calldepth int, appendOutput func([]byte) []byte) error {
 	return err
 }
 
+func init() {
+	internal.DefaultOutput = func(pc uintptr, data []byte) error {
+		return std.output(pc, 0, func(buf []byte) []byte {
+			return append(buf, data...)
+		})
+	}
+}
+
 // Print calls l.Output to print to the logger.
 // Arguments are handled in the manner of fmt.Print.
 func (l *Logger) Print(v ...any) {
-	l.output(2, func(b []byte) []byte {
+	l.output(0, 2, func(b []byte) []byte {
 		return fmt.Append(b, v...)
 	})
 }
@@ -244,7 +265,7 @@ func (l *Logger) Print(v ...any) {
 // Printf calls l.Output to print to the logger.
 // Arguments are handled in the manner of fmt.Printf.
 func (l *Logger) Printf(format string, v ...any) {
-	l.output(2, func(b []byte) []byte {
+	l.output(0, 2, func(b []byte) []byte {
 		return fmt.Appendf(b, format, v...)
 	})
 }
@@ -252,7 +273,7 @@ func (l *Logger) Printf(format string, v ...any) {
 // Println calls l.Output to print to the logger.
 // Arguments are handled in the manner of fmt.Println.
 func (l *Logger) Println(v ...any) {
-	l.output(2, func(b []byte) []byte {
+	l.output(0, 2, func(b []byte) []byte {
 		return fmt.Appendln(b, v...)
 	})
 }
@@ -365,7 +386,7 @@ func Writer() io.Writer {
 // Print calls Output to print to the standard logger.
 // Arguments are handled in the manner of fmt.Print.
 func Print(v ...any) {
-	std.output(2, func(b []byte) []byte {
+	std.output(0, 2, func(b []byte) []byte {
 		return fmt.Append(b, v...)
 	})
 }
@@ -373,7 +394,7 @@ func Print(v ...any) {
 // Printf calls Output to print to the standard logger.
 // Arguments are handled in the manner of fmt.Printf.
 func Printf(format string, v ...any) {
-	std.output(2, func(b []byte) []byte {
+	std.output(0, 2, func(b []byte) []byte {
 		return fmt.Appendf(b, format, v...)
 	})
 }
@@ -381,7 +402,7 @@ func Printf(format string, v ...any) {
 // Println calls Output to print to the standard logger.
 // Arguments are handled in the manner of fmt.Println.
 func Println(v ...any) {
-	std.output(2, func(b []byte) []byte {
+	std.output(0, 2, func(b []byte) []byte {
 		return fmt.Appendln(b, v...)
 	})
 }
diff --git a/src/log/slog/handler.go b/src/log/slog/handler.go
index 87732a90f4..597159e203 100644
--- a/src/log/slog/handler.go
+++ b/src/log/slog/handler.go
@@ -87,11 +87,11 @@ type Handler interface {
 
 type defaultHandler struct {
 	ch *commonHandler
-	// log.Output, except for testing
-	output func(calldepth int, message string) error
+	// internal.DefaultOutput, except for testing
+	output func(pc uintptr, data []byte) error
 }
 
-func newDefaultHandler(output func(int, string) error) *defaultHandler {
+func newDefaultHandler(output func(uintptr, []byte) error) *defaultHandler {
 	return &defaultHandler{
 		ch:     &commonHandler{json: false},
 		output: output,
@@ -113,9 +113,7 @@ func (h *defaultHandler) Handle(ctx context.Context, r Record) error {
 	state := h.ch.newHandleState(buf, true, " ", nil)
 	defer state.free()
 	state.appendNonBuiltIns(r)
-
-	// skip [h.output, defaultHandler.Handle, handlerWriter.Write, log.Output]
-	return h.output(4, buf.String())
+	return h.output(r.PC, *buf)
 }
 
 func (h *defaultHandler) WithAttrs(as []Attr) Handler {
diff --git a/src/log/slog/handler_test.go b/src/log/slog/handler_test.go
index d79d0bf372..2c374d6a20 100644
--- a/src/log/slog/handler_test.go
+++ b/src/log/slog/handler_test.go
@@ -85,8 +85,8 @@ func TestDefaultHandle(t *testing.T) {
 	} {
 		t.Run(test.name, func(t *testing.T) {
 			var got string
-			var h Handler = newDefaultHandler(func(_ int, s string) error {
-				got = s
+			var h Handler = newDefaultHandler(func(_ uintptr, b []byte) error {
+				got = string(b)
 				return nil
 			})
 			if test.with != nil {
diff --git a/src/log/slog/logger.go b/src/log/slog/logger.go
index f58add9af9..7c31cfc97b 100644
--- a/src/log/slog/logger.go
+++ b/src/log/slog/logger.go
@@ -7,6 +7,7 @@ package slog
 import (
 	"context"
 	"log"
+	loginternal "log/internal"
 	"log/slog/internal"
 	"runtime"
 	"sync/atomic"
@@ -16,7 +17,7 @@ import (
 var defaultLogger atomic.Value
 
 func init() {
-	defaultLogger.Store(New(newDefaultHandler(log.Output)))
+	defaultLogger.Store(New(newDefaultHandler(loginternal.DefaultOutput)))
 }
 
 // Default returns the default Logger.
diff --git a/src/log/slog/logger_test.go b/src/log/slog/logger_test.go
index e65071424f..fd20e7ba01 100644
--- a/src/log/slog/logger_test.go
+++ b/src/log/slog/logger_test.go
@@ -11,6 +11,7 @@ import (
 	"internal/testenv"
 	"io"
 	"log"
+	loginternal "log/internal"
 	"path/filepath"
 	"regexp"
 	"runtime"
@@ -70,7 +71,7 @@ func TestConnections(t *testing.T) {
 	// tests might change the default logger using SetDefault. Also ensure we
 	// restore the default logger at the end of the test.
 	currentLogger := Default()
-	SetDefault(New(newDefaultHandler(log.Output)))
+	SetDefault(New(newDefaultHandler(loginternal.DefaultOutput)))
 	t.Cleanup(func() {
 		SetDefault(currentLogger)
 	})
@@ -94,16 +95,8 @@ func TestConnections(t *testing.T) {
 
 	t.Run("wrap default handler", func(t *testing.T) {
 		// It should be possible to wrap the default handler and get the right output.
-		// But because the call depth to log.Output is hard-coded, the source line is wrong.
-		// We want to use the pc inside the Record, but there is no way to give that to
-		// the log package.
-		//
-		// TODO(jba): when slog lives under log in the standard library, we can
-		// move the bulk of log.Logger.Output to a function in an internal
-		// package, so both log and slog can call it.
-		//
-		// While slog lives in exp, we punt.
-		t.Skip("skip until this package is in the standard library")
+		// This works because the default handler uses the pc in the Record
+		// to get the source line, rather than a call depth.
 		logger := New(wrappingHandler{Default().Handler()})
 		logger.Info("msg", "d", 4)
 		checkLogOutput(t, logbuf.String(), `logger_test.go:\d+: INFO msg d=4`)