diff --git a/src/window.cpp b/src/window.cpp
--- a/src/window.cpp
+++ b/src/window.cpp
@@ -1079,7 +1079,16 @@ Window::~Window()
 	free(this->nested_array); // Contents is released through deletion of #nested_root.
 	delete this->nested_root;
 
-	this->window_class = WC_INVALID;
+	/*
+	 * Make fairly sure that this is written, and not "optimized" away.
+	 * The delete operator is overwritten to not delete it; the deletion
+	 * happens at a later moment in time after the window has been
+	 * removed from the list of windows to prevent issues with items
+	 * being removed during the iteration as not one but more windows
+	 * may be removed by a single call to ~Window by means of the
+	 * DeleteChildWindows function.
+	 */
+	const_cast<volatile WindowClass &>(this->window_class) = WC_INVALID;
 }
 
 /**