diff --git a/hugolib/config.go b/hugolib/config.go
index 122bd3f1e..3a0e665c1 100644
--- a/hugolib/config.go
+++ b/hugolib/config.go
@@ -471,7 +471,7 @@ func loadDefaultSettingsFor(v *viper.Viper) error {
 	v.SetDefault("disableFastRender", false)
 	v.SetDefault("timeout", 10000) // 10 seconds
 
-	// Remove in Hugo 0.39
+	// Remove in Hugo 0.50
 
 	if v.GetBool("useModTimeAsFallback") {
 
@@ -480,7 +480,7 @@ func loadDefaultSettingsFor(v *viper.Viper) error {
 [frontmatter]
 date = [ "date",":fileModTime", ":default"]
 lastmod = ["lastmod" ,":fileModTime", ":default"]
-`, false)
+`, true)
 
 	}
 
diff --git a/hugolib/rss_test.go b/hugolib/rss_test.go
index d02d98a21..db26c7d2d 100644
--- a/hugolib/rss_test.go
+++ b/hugolib/rss_test.go
@@ -30,10 +30,9 @@ func TestRSSOutput(t *testing.T) {
 
 	rssLimit := len(weightedSources) - 1
 
-	rssURI := "customrss.xml"
+	rssURI := "index.xml"
 
 	cfg.Set("baseURL", "http://auth/bub/")
-	cfg.Set("rssURI", rssURI)
 	cfg.Set("title", "RSSTest")
 	cfg.Set("rssLimit", rssLimit)
 
diff --git a/hugolib/site_output.go b/hugolib/site_output.go
index f81162e43..0e0fe76a7 100644
--- a/hugolib/site_output.go
+++ b/hugolib/site_output.go
@@ -15,11 +15,8 @@ package hugolib
 
 import (
 	"fmt"
-	"path"
-	"strings"
 
 	"github.com/gohugoio/hugo/config"
-	"github.com/gohugoio/hugo/helpers"
 	"github.com/gohugoio/hugo/output"
 	"github.com/spf13/cast"
 )
@@ -30,20 +27,6 @@ func createDefaultOutputFormats(allFormats output.Formats, cfg config.Provider)
 	robotsOut, _ := allFormats.GetByName(output.RobotsTxtFormat.Name)
 	sitemapOut, _ := allFormats.GetByName(output.SitemapFormat.Name)
 
-	// TODO(bep) this mumbo jumbo is deprecated and should be removed, but there are tests that
-	// depends on this, so that will have to wait.
-	rssBase := cfg.GetString("rssURI")
-	if rssBase == "" || rssBase == "index.xml" {
-		rssBase = rssOut.BaseName
-	} else {
-		// Remove in Hugo 0.36.
-		helpers.Deprecated("Site config", "rssURI", "Set baseName in outputFormats.RSS", true)
-		// RSS has now a well defined media type, so strip any suffix provided
-		rssBase = strings.TrimSuffix(rssBase, path.Ext(rssBase))
-	}
-
-	rssOut.BaseName = rssBase
-
 	return map[string]output.Formats{
 		KindPage:         output.Formats{htmlOut},
 		KindHome:         output.Formats{htmlOut, rssOut},