diff --git a/modules/ext.isekai.function-btn.js b/modules/ext.isekai.function-btn.js
index 924622e..5371129 100644
--- a/modules/ext.isekai.function-btn.js
+++ b/modules/ext.isekai.function-btn.js
@@ -16,7 +16,7 @@ function onFullScreenChange() {
 $(function () {
     if (mw.config.get('wgIsArticle')) {
         var fullScreenIcon = new OO.ui.IconWidget({ icon: 'fullScreen' });
-        var exitFullScreenIcon = new OO.ui.IconWidget({ icon: 'exitFullScreen' });
+        var exitFullScreenIcon = new OO.ui.IconWidget({ icon: 'exitFullscreen' });
 
         fullScreenBtn = isekai.bottomNav.addButton({
             id: 'fullscreen',