diff --git a/lib/ini.js b/lib/ini.js
index b0be0b3..965e702 100644
--- a/lib/ini.js
+++ b/lib/ini.js
@@ -182,9 +182,8 @@ const unsafe = (val, doUnesc) => {
   if (isQuoted(val)) {
     // remove the single quotes before calling JSON.parse
     if (val.charAt(0) === "'") {
-      val = val.substr(1, val.length - 2)
+      val = val.slice(1, -1)
     }
-
     try {
       val = JSON.parse(val)
     } catch (_) {}