diff --git a/main.go b/main.go
index 6b04831..e156801 100644
--- a/main.go
+++ b/main.go
@@ -25,7 +25,6 @@ package main
 import (
 	"bufio"
 	"encoding/json"
-	"flag"
 	"fmt"
 	"io"
 	"log"
@@ -33,6 +32,7 @@ import (
 	"os"
 	"path/filepath"
 	"sort"
+	"strconv"
 	"strings"
 	"text/template"
 	"time"
@@ -605,9 +605,17 @@ func main() {
 	}
 
 	//delay := flag.Duration("delay", defaultDelay, "delay between downloads (e.g. 5s, 1m)")
-	delay := os.Getenv("DELAY")
-	if delay == "" {
+	var delay time.Duration
+	delayStr := os.Getenv("DELAY")
+	if delayStr == "" {
 		delay = defaultDelay
+	} else {
+		secs, err := strconv.Atoi(delayStr)
+		if err != nil || secs <= 0 {
+			log.Printf("invalid DELAY=%q, using default (%v)", delayStr, defaultDelay)
+		} else {
+			delay = time.Duration(secs) * time.Second
+		}
 	}
 
 	//outDir := flag.String("out", "./lists/", "target directory")