diff --git a/mods/pixelResizeTool.js b/mods/pixelResizeTool.js
index beccf27c..758a8c62 100644
--- a/mods/pixelResizeTool.js
+++ b/mods/pixelResizeTool.js
@@ -3,7 +3,7 @@ pixelResizeButton.onclick = function(pixel) {
     let canvas_width = document.getElementById("game").width;
     let canvas_height = document.getElementById("game").height;
     let pixelSizeNeeded = prompt("How big should pixels be?");
-    if (!pixelSizeNeeded || isNAN(pixelSizeNeeded)) { alert('number is invalid!'); return; }
+    if (!pixelSizeNeeded || isNaN(pixelSizeNeeded)) { alert('number is invalid!'); return; }
     resizeCanvas(canvas_height,canvas_width, parseFloat(pixelSizeNeeded), true);
 };
 pixelResizeButton.textContent = "Resize";