diff --git a/src/cache/cache.go b/src/cache/cache.go
index 4399eee..a6970f2 100644
--- a/src/cache/cache.go
+++ b/src/cache/cache.go
@@ -5,7 +5,6 @@ import (
 	"encoding/hex"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"log"
 	"mime"
 	"net/http"
@@ -145,8 +144,9 @@ func (c *Cache) Close() {
 	c.waitGroup.Wait()
 }
 
+// Migrate converts old files to newer format
 func (c *Cache) Migrate(pathname *string) (err error) {
-	files, err := ioutil.ReadDir(*pathname)
+	files, err := os.ReadDir(*pathname)
 	for _, f := range files {
 		if strings.HasSuffix(f.Name(), ".json") {
 			basename := strings.Split(f.Name(), ".")[0]