diff --git a/extension.js b/extension.js
index a7a0b44..86c340e 100644
--- a/extension.js
+++ b/extension.js
@@ -15,9 +15,16 @@
 
 const {Clutter, Gio, Meta} = imports.gi;
 
-const Workspace                  = imports.ui.workspace.Workspace;
-const WindowManager              = imports.ui.windowManager.WindowManager;
-const WINDOW_REPOSITIONING_DELAY = imports.ui.workspace.WINDOW_REPOSITIONING_DELAY;
+const Workspace     = imports.ui.workspace.Workspace;
+const WindowManager = imports.ui.windowManager.WindowManager;
+
+// The WindowPreview class is only available on GNOME Shell 3.38+;
+let WindowPreview = null;
+try {
+  WindowPreview = imports.ui.windowPreview.WindowPreview;
+} catch (error) {
+  // Nothing to be done, we are on GNOME Shell 3.36.
+}
 
 const ExtensionUtils = imports.misc.extensionUtils;
 const Me             = imports.misc.extensionUtils.getCurrentExtension();
@@ -69,6 +76,18 @@ class Extension {
     // the WorkspacesView.
     const extensionThis = this;
 
+    // Do not attempt to close windows twice. Due to the animation in the overview, the
+    // close button can be clicked twice which normally would lead to a crash.
+    if (WindowPreview) {
+      this._origDeleteAll = WindowPreview.prototype._deleteAll;
+
+      WindowPreview.prototype._deleteAll = function() {
+        if (!this._closeRequested) {
+          extensionThis._origDeleteAll.apply(this);
+        }
+      };
+    }
+
     // On GNOME 3.36, the window clone's 'destroy' handler only calls _removeWindowClone
     // but not _doRemoveWindow. The latter is required to trigger the repositioning of the
     // overview window layout. Therefore we call this method in addition.
@@ -187,6 +206,10 @@ class Extension {
     Workspace.prototype._addWindowClone         = this._origAddWindowClone;
     WindowManager.prototype._shouldAnimateActor = this._origShouldAnimateActor;
 
+    if (WindowPreview) {
+      WindowPreview.prototype._deleteAll = this._origDeleteAll;
+    }
+
     this._settings = null;
   }