diff --git a/web/fup/cmd/serve.go b/web/fup/cmd/serve.go
index 2ab5e5b7e3..6a69106432 100644
--- a/web/fup/cmd/serve.go
+++ b/web/fup/cmd/serve.go
@@ -15,6 +15,7 @@ import (
 	"github.com/coreos/go-systemd/v22/activation"
 	"github.com/google/safehtml"
 	"github.com/spf13/cobra"
+	"github.com/spf13/viper"
 	"hg.lukegb.com/lukegb/depot/web/fup/fuphttp"
 	"hg.lukegb.com/lukegb/depot/web/fup/fupstatic"
 	"hg.lukegb.com/lukegb/depot/web/fup/minicheddar"
@@ -24,12 +25,18 @@ func init() {
 	rootCmd.AddCommand(serveCmd)
 
 	serveCmd.Flags().StringVar(&serveRoot, "root", "http://localhost:8191/", "Application root address.")
+	viper.BindPFlag("serve.app-root", serveCmd.Flags().Lookup("root"))
 	serveCmd.Flags().StringVar(&serveStaticRoot, "static-root", "/static/", "Root address from which static assets should be referenced.")
+	viper.BindPFlag("serve.static-root", serveCmd.Flags().Lookup("static-root"))
 	serveCmd.Flags().StringVarP(&serveBind, "listen", "l", ":8191", "Bind address for HTTP server.")
+	viper.BindPFlag("serve.listen", serveCmd.Flags().Lookup("listen"))
 	serveCmd.Flags().BoolVar(&serveDirectOnly, "direct-only", false, "If set, all file serving will be proxied, even if the backend supports signed URLs.")
+	viper.BindPFlag("serve.direct-only", serveCmd.Flags().Lookup("direct-only"))
 
 	serveCmd.Flags().StringVar(&serveCheddarPath, "cheddar-path", "cheddar", "Path to 'cheddar' binary to use for syntax highlighting. If it cannot be found, syntax highlighting and markdown rendering will be disabled.")
+	viper.BindPFlag("serve.cheddar.path", serveCmd.Flags().Lookup("cheddar-path"))
 	serveCmd.Flags().StringVar(&serveCheddarAddr, "cheddar-address", "", "If non-empty, will be used instead of attempting to spawn a copy of cheddar.")
+	viper.BindPFlag("serve.cheddar.address", serveCmd.Flags().Lookup("cheddar-address"))
 }
 
 var (