diff --git a/doc/effective_go.html b/doc/effective_go.html
index 8ce72fc196..e825f747ab 100644
--- a/doc/effective_go.html
+++ b/doc/effective_go.html
@@ -1,4 +1,9 @@
 <!-- Effective Go -->
+<!--
+  DO NOT EDIT: created by
+    tmpltohtml effective_go.tmpl
+-->
+
 
 <h2 id="introduction">Introduction</h2>
 
diff --git a/doc/effective_go.tmpl b/doc/effective_go.tmpl
index bd19f95d34..8ca4902c3b 100644
--- a/doc/effective_go.tmpl
+++ b/doc/effective_go.tmpl
@@ -1,4 +1,5 @@
 <!-- Effective Go -->
+{{donotedit}}
 
 <h2 id="introduction">Introduction</h2>
 
diff --git a/doc/go_tutorial.html b/doc/go_tutorial.html
index 423abe8b0a..145ea21106 100644
--- a/doc/go_tutorial.html
+++ b/doc/go_tutorial.html
@@ -1,4 +1,10 @@
 <!-- A Tutorial for the Go Programming Language -->
+<!--
+  DO NOT EDIT: created by
+    tmpltohtml go_tutorial.tmpl
+-->
+
+
 <h2>Introduction</h2>
 <p>
 This document is a tutorial introduction to the basics of the Go programming
diff --git a/doc/go_tutorial.tmpl b/doc/go_tutorial.tmpl
index d1219b47ed..2a583e2f49 100644
--- a/doc/go_tutorial.tmpl
+++ b/doc/go_tutorial.tmpl
@@ -1,4 +1,6 @@
 <!-- A Tutorial for the Go Programming Language -->
+{{donotedit}}
+
 <h2>Introduction</h2>
 <p>
 This document is a tutorial introduction to the basics of the Go programming
diff --git a/doc/tmpltohtml.go b/doc/tmpltohtml.go
index 1e3424cf5e..84a47d6ed2 100644
--- a/doc/tmpltohtml.go
+++ b/doc/tmpltohtml.go
@@ -35,6 +35,11 @@ func Usage() {
 	os.Exit(2)
 }
 
+var templateFuncs = template.FuncMap{
+	"code":      code,
+	"donotedit": donotedit,
+}
+
 func main() {
 	flag.Usage = Usage
 	flag.Parse()
@@ -44,7 +49,7 @@ func main() {
 
 	// Read and parse the input.
 	name := flag.Args()[0]
-	tmpl := template.New(name).Funcs(template.FuncMap{"code": code})
+	tmpl := template.New(name).Funcs(templateFuncs)
 	if _, err := tmpl.ParseFiles(name); err != nil {
 		log.Fatal(err)
 	}
@@ -80,6 +85,11 @@ func format(arg interface{}) string {
 	return ""
 }
 
+func donotedit() string {
+	// No editing please.
+	return fmt.Sprintf("<!--\n  DO NOT EDIT: created by\n    tmpltohtml %s\n-->\n", flag.Args()[0])
+}
+
 func code(file string, arg ...interface{}) (string, error) {
 	text := contents(file)
 	var command string