diff --git a/src/public/Terminal.ts b/src/public/Terminal.ts
index b72a4cff4..fe34cb36f 100644
--- a/src/public/Terminal.ts
+++ b/src/public/Terminal.ts
@@ -181,7 +181,7 @@ export class Terminal implements ITerminalApi {
 
   private _verifyIntegers(...values: number[]): void {
     values.forEach(value => {
-      if (value === Infinity || value === NaN || value % 1 !== 0) {
+      if (value === Infinity || isNaN(value) || value % 1 !== 0) {
         throw new Error('This API only accepts integers');
       }
     });