diff --git a/src/modals/SelectMapModal.js b/src/modals/SelectMapModal.js
index 6e988ac..2236bc5 100644
--- a/src/modals/SelectMapModal.js
+++ b/src/modals/SelectMapModal.js
@@ -127,7 +127,7 @@ function SelectMapModal({
     return new Promise((resolve, reject) => {
       image.onload = async function () {
         // Find name and grid size
-        let gridSize = { x: 22, y: 22 };
+        let gridSize;
         let name = "Unknown Map";
         if (file.name) {
           if (file.name.matchAll) {
@@ -162,6 +162,10 @@ function SelectMapModal({
           name = Case.capital(name);
         }
 
+        if (!gridSize) {
+          gridSize = { x: 22, y: 22 };
+        }
+
         // Create resolutions
         const resolutions = {};
         for (let resolution of mapResolutions) {