diff --git a/src/main.ts b/src/main.ts
index 922225e..b08ebb2 100644
--- a/src/main.ts
+++ b/src/main.ts
@@ -41,7 +41,7 @@ export default class ImageToolkitPlugin extends Plugin {
       this.app.workspace.iterateAllLeaves((leaf: WorkspaceLeaf) => {
         if (['markdown', 'image'].includes(leaf.getViewState()?.type)) {
           const bodyEl = leaf.view.containerEl.matchParent('body');
-          if (bodyEl.hasClass('is-popout-window')) {
+          if (bodyEl?.hasClass('is-popout-window')) {
             if (!bodyEl.hasAttribute(ImageToolkitPlugin.POPOUT_WINDOW_EVENT)) {
               console.log('popout leaf:', leaf, leaf.getDisplayText());
               const eventId = randomUUID();