diff --git a/lib/types/json.js b/lib/types/json.js
index 30bf8cab..901b16c6 100644
--- a/lib/types/json.js
+++ b/lib/types/json.js
@@ -189,11 +189,8 @@ function createStrictSyntaxError (str, char) {
  */
 
 function firstchar (str) {
-  var match = FIRST_CHAR_REGEXP.exec(str)
-
-  return match
-    ? match[1]
-    : undefined
+  const match = FIRST_CHAR_REGEXP.exec(str)
+  return match?.[1]
 }
 
 /**
@@ -244,7 +241,5 @@ function normalizeJsonSyntaxError (error, obj) {
  */
 
 function typeChecker (type) {
-  return function checkType (req) {
-    return Boolean(typeis(req, type))
-  }
+  return (req) => Boolean(typeis(req, type))
 }