diff --git a/lib/serializer.js b/lib/serializer.js
index 387e8927..c6865226 100644
--- a/lib/serializer.js
+++ b/lib/serializer.js
@@ -25,13 +25,12 @@ module.exports = class Serializer {
 
   asInteger (i) {
     if (typeof i === 'number') {
-      if (i === Infinity || i === -Infinity) {
-        throw new Error(`The value "${i}" cannot be converted to an integer.`)
-      }
       if (Number.isInteger(i)) {
         return '' + i
       }
-      if (Number.isNaN(i)) {
+      // check if number is Infinity or NaN
+      // eslint-disable-next-line no-self-compare
+      if (i === Infinity || i === -Infinity || i !== i) {
         throw new Error(`The value "${i}" cannot be converted to an integer.`)
       }
       return this.parseInteger(i)
@@ -52,7 +51,9 @@ module.exports = class Serializer {
 
   asNumber (i) {
     const num = Number(i)
-    if (Number.isNaN(num)) {
+    // check if number is NaN
+    // eslint-disable-next-line no-self-compare
+    if (num !== num) {
       throw new Error(`The value "${i}" cannot be converted to a number.`)
     } else if (!Number.isFinite(num)) {
       return 'null'