diff --git a/lib/file.js b/lib/file.js
index 24e140779..2342fd3ab 100644
--- a/lib/file.js
+++ b/lib/file.js
@@ -36,7 +36,7 @@ class File {
    * @returns {string} detected file type or empty string
    */
   detectType () {
-    return path.extname(this.path).substring(1)
+    return path.extname(this.path).slice(1)
   }
 
   toString () {
diff --git a/lib/helper.js b/lib/helper.js
index 3c58fe8dc..9be119378 100644
--- a/lib/helper.js
+++ b/lib/helper.js
@@ -30,15 +30,15 @@ const parser = (pattern, out) => {
       t = 'optional'
     }
     out[t]++
-    return parser(pattern.substring(1), out)
+    return parser(pattern.slice(1), out)
   }
   if (matches[2] !== undefined) {
     out.ext_glob++
     parser(matches[2], out)
-    return parser(pattern.substring(matches[0].length), out)
+    return parser(pattern.slice(matches[0].length), out)
   }
   out.range++
-  return parser(pattern.substring(matches[0].length), out)
+  return parser(pattern.slice(matches[0].length), out)
 }
 
 const gsParser = (pattern, out) => {
diff --git a/lib/launchers/process.js b/lib/launchers/process.js
index a7aa101ce..9fa859fc3 100644
--- a/lib/launchers/process.js
+++ b/lib/launchers/process.js
@@ -44,7 +44,7 @@ function ProcessLauncher (spawn, tempDir, timer, processKillTimeout) {
   // Normalize the command, remove quotes (spawn does not like them).
   this._normalizeCommand = function (cmd) {
     if (cmd.charAt(0) === cmd.charAt(cmd.length - 1) && '\'`"'.includes(cmd.charAt(0))) {
-      cmd = cmd.substring(1, cmd.length - 1)
+      cmd = cmd.slice(1, -1)
       log.warn(`The path should not be quoted.\n  Normalized the path to ${cmd}`)
     }
 
diff --git a/lib/url.js b/lib/url.js
index 0bbfcc6d3..ebe078619 100644
--- a/lib/url.js
+++ b/lib/url.js
@@ -19,7 +19,7 @@ class Url {
    * @returns {string} detected file type or empty string
    */
   detectType () {
-    return path.extname(new URL(this.path).pathname).substring(1)
+    return path.extname(new URL(this.path).pathname).slice(1)
   }
 
   toString () {