diff --git a/src/go/build/deps_test.go b/src/go/build/deps_test.go
index 2c29a3e6018f77..9d6d038dab1213 100644
--- a/src/go/build/deps_test.go
+++ b/src/go/build/deps_test.go
@@ -192,10 +192,11 @@ var pkgDeps = map[string][]string{
 	"runtime/trace":  {"L0", "context", "fmt"},
 	"text/tabwriter": {"L2"},
 
-	"testing":          {"L2", "flag", "fmt", "internal/race", "os", "runtime/debug", "runtime/pprof", "runtime/trace", "time"},
-	"testing/iotest":   {"L2", "log"},
-	"testing/quick":    {"L2", "flag", "fmt", "reflect", "time"},
-	"internal/testenv": {"L2", "OS", "flag", "testing", "syscall"},
+	"testing":             {"L2", "flag", "fmt", "internal/race", "os", "runtime/debug", "runtime/pprof", "runtime/trace", "time"},
+	"testing/iotest":      {"L2", "log"},
+	"testing/quick":       {"L2", "flag", "fmt", "reflect", "time"},
+	"internal/testenv":    {"L2", "OS", "flag", "testing", "syscall"},
+	"internal/lazyregexp": {"L2", "OS", "regexp"},
 
 	// L4 is defined as L3+fmt+log+time, because in general once
 	// you're using L3 packages, use of fmt, log, or time is not a big deal.
@@ -208,7 +209,7 @@ var pkgDeps = map[string][]string{
 
 	// Go parser.
 	"go/ast":     {"L4", "OS", "go/scanner", "go/token"},
-	"go/doc":     {"L4", "OS", "go/ast", "go/token", "regexp", "text/template"},
+	"go/doc":     {"L4", "OS", "go/ast", "go/token", "regexp", "internal/lazyregexp", "text/template"},
 	"go/parser":  {"L4", "OS", "go/ast", "go/scanner", "go/token"},
 	"go/printer": {"L4", "OS", "go/ast", "go/scanner", "go/token", "text/tabwriter"},
 	"go/scanner": {"L4", "OS", "go/token"},
diff --git a/src/go/doc/comment.go b/src/go/doc/comment.go
index 73857330fa7158..31ee93e44f819e 100644
--- a/src/go/doc/comment.go
+++ b/src/go/doc/comment.go
@@ -8,6 +8,7 @@ package doc
 
 import (
 	"bytes"
+	"internal/lazyregexp"
 	"io"
 	"strings"
 	"text/template" // for HTMLEscape
@@ -69,7 +70,7 @@ const (
 	urlRx = protoPart + `://` + hostPart + pathPart
 )
 
-var matchRx = newLazyRE(`(` + urlRx + `)|(` + identRx + `)`)
+var matchRx = lazyregexp.New(`(` + urlRx + `)|(` + identRx + `)`)
 
 var (
 	html_a      = []byte(`<a href="`)
@@ -273,7 +274,7 @@ type block struct {
 	lines []string
 }
 
-var nonAlphaNumRx = newLazyRE(`[^a-zA-Z0-9]`)
+var nonAlphaNumRx = lazyregexp.New(`[^a-zA-Z0-9]`)
 
 func anchorID(line string) string {
 	// Add a "hdr-" prefix to avoid conflicting with IDs used for package symbols.
diff --git a/src/go/doc/reader.go b/src/go/doc/reader.go
index 6db5c21c4a222c..49d2af771a09cc 100644
--- a/src/go/doc/reader.go
+++ b/src/go/doc/reader.go
@@ -7,6 +7,7 @@ package doc
 import (
 	"go/ast"
 	"go/token"
+	"internal/lazyregexp"
 	"sort"
 	"strconv"
 )
@@ -439,9 +440,9 @@ func (r *reader) readFunc(fun *ast.FuncDecl) {
 }
 
 var (
-	noteMarker    = `([A-Z][A-Z]+)\(([^)]+)\):?`           // MARKER(uid), MARKER at least 2 chars, uid at least 1 char
-	noteMarkerRx  = newLazyRE(`^[ \t]*` + noteMarker)      // MARKER(uid) at text start
-	noteCommentRx = newLazyRE(`^/[/*][ \t]*` + noteMarker) // MARKER(uid) at comment start
+	noteMarker    = `([A-Z][A-Z]+)\(([^)]+)\):?`                // MARKER(uid), MARKER at least 2 chars, uid at least 1 char
+	noteMarkerRx  = lazyregexp.New(`^[ \t]*` + noteMarker)      // MARKER(uid) at text start
+	noteCommentRx = lazyregexp.New(`^/[/*][ \t]*` + noteMarker) // MARKER(uid) at comment start
 )
 
 // readNote collects a single note from a sequence of comments.
diff --git a/src/go/doc/lazyre.go b/src/internal/lazyregexp/lazyre.go
similarity index 66%
rename from src/go/doc/lazyre.go
rename to src/internal/lazyregexp/lazyre.go
index 3fd97d42de6887..e4170683ebc8bc 100644
--- a/src/go/doc/lazyre.go
+++ b/src/internal/lazyregexp/lazyre.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-package doc
+package lazyregexp
 
 import (
 	"os"
@@ -11,38 +11,38 @@ import (
 	"sync"
 )
 
-type lazyRE struct {
+type Regexp struct {
 	str  string
 	once sync.Once
 	rx   *regexp.Regexp
 }
 
-func (r *lazyRE) re() *regexp.Regexp {
+func (r *Regexp) re() *regexp.Regexp {
 	r.once.Do(r.build)
 	return r.rx
 }
 
-func (r *lazyRE) build() {
+func (r *Regexp) build() {
 	r.rx = regexp.MustCompile(r.str)
 	r.str = ""
 }
 
-func (r *lazyRE) FindStringSubmatchIndex(s string) []int {
+func (r *Regexp) FindStringSubmatchIndex(s string) []int {
 	return r.re().FindStringSubmatchIndex(s)
 }
 
-func (r *lazyRE) ReplaceAllString(src, repl string) string {
+func (r *Regexp) ReplaceAllString(src, repl string) string {
 	return r.re().ReplaceAllString(src, repl)
 }
 
-func (r *lazyRE) MatchString(s string) bool {
+func (r *Regexp) MatchString(s string) bool {
 	return r.re().MatchString(s)
 }
 
 var inTest = len(os.Args) > 0 && strings.HasSuffix(strings.TrimSuffix(os.Args[0], ".exe"), ".test")
 
-func newLazyRE(str string) *lazyRE {
-	lr := &lazyRE{str: str}
+func New(str string) *Regexp {
+	lr := &Regexp{str: str}
 	if inTest {
 		// In tests, always compile the regexps early.
 		lr.re()