diff --git a/tpl/tplimpl/ace.go b/tpl/tplimpl/ace.go
index bdbc71059..5aa9fe2cb 100644
--- a/tpl/tplimpl/ace.go
+++ b/tpl/tplimpl/ace.go
@@ -18,10 +18,13 @@ import (
 
 	"strings"
 
+	"github.com/gohugoio/hugo/helpers"
+
 	"github.com/yosssi/ace"
 )
 
 func (t *templateHandler) addAceTemplate(name, basePath, innerPath string, baseContent, innerContent []byte) error {
+	helpers.Deprecated("Ace", "See https://github.com/gohugoio/hugo/issues/6609", false)
 	t.checkState()
 	var base, inner *ace.File
 	withoutExt := name[:len(name)-len(filepath.Ext(innerPath))]
diff --git a/tpl/tplimpl/amber_compiler.go b/tpl/tplimpl/amber_compiler.go
index b37becb3d..c9362e7df 100644
--- a/tpl/tplimpl/amber_compiler.go
+++ b/tpl/tplimpl/amber_compiler.go
@@ -16,11 +16,14 @@ package tplimpl
 import (
 	"html/template"
 
+	"github.com/gohugoio/hugo/helpers"
+
 	"github.com/eknkc/amber"
 	"github.com/spf13/afero"
 )
 
 func (t *templateHandler) compileAmberWithTemplate(b []byte, path string, templ *template.Template) (*template.Template, error) {
+	helpers.Deprecated("Amber", "See https://github.com/gohugoio/hugo/issues/6609", false)
 	c := amber.New()
 	c.Options.VirtualFilesystem = afero.NewHttpFs(t.layoutsFs)