diff --git a/generate/generate.go b/generate/generate.go
index f48c8fc..4dea088 100644
--- a/generate/generate.go
+++ b/generate/generate.go
@@ -21,6 +21,12 @@ import (
 	"strings"
 )
 
+const header = `/*
+Generated by https://code.squareroundforest.org/arpio/docreflect
+*/
+
+`
+
 type options struct {
 	wd      string
 	goroot  string
@@ -600,6 +606,7 @@ func format(w io.Writer, pname string, docs map[string]string) error {
 		_, err = fmt.Fprintln(w, a...)
 	}
 
+	println(header)
 	printf("package %s\n", pname)
 	println("import \"code.squareroundforest.org/arpio/docreflect\"")
 	println("func init() {")
diff --git a/generate/generate_test.go b/generate/generate_test.go
index 2650038..32a76ba 100644
--- a/generate/generate_test.go
+++ b/generate/generate_test.go
@@ -404,12 +404,12 @@ func TestFormat(t *testing.T) {
 	}
 
 	o := b.String()
-	if o != `package testpackage
+	if !strings.Contains(o, `package testpackage
 import "code.squareroundforest.org/arpio/docreflect"
 func init() {
 docreflect.Register("baz", "qux")
 docreflect.Register("foo", "bar")
-}` {
-		t.Fatal()
+}`) {
+		t.Fatal(o)
 	}
 }