diff --git a/ui/views/widget/widget.cc b/ui/views/widget/widget.cc
index bf4b1d0..a3b72c4 100644
@@ -995,7 +996,8 @@

 void Widget::OnSizeConstraintsChanged() {
   native_widget_->OnSizeConstraintsChanged();
-  non_client_view_->SizeConstraintsChanged();
+  if (non_client_view_)
+    non_client_view_->SizeConstraintsChanged();
 }

 void Widget::OnOwnerClosing() {}