diff --git a/src/window.cpp b/src/window.cpp
index 86b7743648..00e42ff722 100644
--- a/src/window.cpp
+++ b/src/window.cpp
@@ -208,7 +208,7 @@ void Window::RaiseButtons()
 	}
 	if (this->nested_array != NULL) {
 		for (uint i = 0; i < this->nested_array_size; i++) {
-			if (this->IsWidgetLowered(i)) {
+			if (this->nested_array[i] != NULL && this->IsWidgetLowered(i)) {
 				this->RaiseWidget(i);
 				this->InvalidateWidget(i);
 			}
diff --git a/src/window_gui.h b/src/window_gui.h
index 846a5a2db1..45ef5b8f79 100644
--- a/src/window_gui.h
+++ b/src/window_gui.h
@@ -274,7 +274,7 @@ public:
 		}
 		if (this->nested_array != NULL) {
 			assert(widget_index < this->nested_array_size);
-			this->nested_array[widget_index]->SetDisabled(disab_stat);
+			if (this->nested_array[widget_index] != NULL) this->nested_array[widget_index]->SetDisabled(disab_stat);
 		}
 	}