diff --git a/cmd/packserver/main.go b/cmd/packserver/main.go
index c18b90b..2000102 100644
--- a/cmd/packserver/main.go
+++ b/cmd/packserver/main.go
@@ -5,12 +5,17 @@ package main
 
 import (
 	"bufio"
+	"context"
 	"errors"
 	"fmt"
 	"net/http"
 	"os"
+	"os/signal"
 	"path/filepath"
 	"strings"
+	"sync/atomic"
+	"syscall"
+	"time"
 
 	"github.com/spf13/cobra"
 	"src.lwithers.me.uk/go/htpack"
@@ -53,6 +58,8 @@ func main() {
 		"Name of file to return if response would be 404 (spa.html or similar)")
 	rootCmd.Flags().String("frames", "sameorigin",
 		"Override X-Frame-Options header (can be sameorigin, deny, allow)")
+	rootCmd.Flags().Duration("graceful-shutdown-delay", 3*time.Second,
+		"Number of seconds to wait after receiving SIGTERM before initiating graceful shutdown")
 
 	if err := rootCmd.Execute(); err != nil {
 		fmt.Fprintln(os.Stderr, err)
@@ -151,6 +158,15 @@ func run(c *cobra.Command, args []string) error {
 		return err
 	}
 
+	// graceful shutdown delay must be > 0
+	gracefulShutdownDelay, err := c.Flags().GetDuration("graceful-shutdown-delay")
+	if err != nil {
+		return err
+	}
+	if gracefulShutdownDelay <= 0 {
+		return errors.New("graceful shutdown delay must be > 0s")
+	}
+
 	// verify .htpack specifications
 	if len(args) == 0 {
 		return errors.New("must specify one or more .htpack files")
@@ -176,6 +192,7 @@ func run(c *cobra.Command, args []string) error {
 	}
 
 	// load packfiles, registering handlers as we go
+	var handler http.Handler
 	for prefix, packfile := range packPaths {
 		packHandler, err := htpack.New(packfile)
 		if err != nil {
@@ -190,26 +207,58 @@ func run(c *cobra.Command, args []string) error {
 		}
 		packHandler.SetHeader("X-Frame-Options", framesHeader)
 
-		handler := &addHeaders{
+		handler = &addHeaders{
 			extraHeaders: extraHeaders,
 			handler:      packHandler,
 		}
 
 		if prefix != "/" {
-			http.Handle(prefix+"/",
-				http.StripPrefix(prefix, handler))
-		} else {
-			http.Handle("/", handler)
+			handler = http.StripPrefix(prefix, handler)
 		}
 	}
 
+	// HTTP server object setup
+	sv := &http.Server{
+		Addr:    bindAddr,
+		Handler: handler,
+	}
+
+	// register SIGINT, SIGTERM handler
+	sigch := make(chan os.Signal, 1)
+	signal.Notify(sigch, syscall.SIGINT, syscall.SIGTERM)
+	var (
+		// if we are shut down by a signal, then http.ListenAndServe()
+		// returns straight away, but we actually need to wait for
+		// Shutdown() to complete prior to returning / exiting
+		isSignalled atomic.Bool
+		signalDone  = make(chan struct{})
+	)
+	go func() {
+		<-sigch
+		time.Sleep(gracefulShutdownDelay)
+		isSignalled.Store(true)
+		shutctx, shutcancel := context.WithTimeout(context.Background(), gracefulShutdownDelay)
+		sv.Shutdown(shutctx)
+		shutcancel()
+		close(signalDone)
+	}()
+
 	// main server loop
 	if keyFile == "" {
-		err = http.ListenAndServe(bindAddr, nil)
+		err = sv.ListenAndServe()
 	} else {
-		err = http.ListenAndServeTLS(bindAddr, certFile, keyFile, nil)
+		err = sv.ListenAndServeTLS(certFile, keyFile)
 	}
-	if err != nil {
+
+	// if we were shut down by a signal, wait for Shutdown() to return
+	if isSignalled.Load() {
+		<-signalDone
+	}
+
+	switch err {
+	case nil, http.ErrServerClosed:
+		// OK
+	default:
 		fmt.Fprintln(os.Stderr, err)
 		os.Exit(1)
 	}