diff --git a/src/widget.cpp b/src/widget.cpp
--- a/src/widget.cpp
+++ b/src/widget.cpp
@@ -3254,6 +3254,8 @@ static const NWidgetPart *MakeNWidget(co
 
 				NWidgetBackground *nwb = dynamic_cast<NWidgetBackground *>(*dest);
 				if (nwb != nullptr) nwb->SetPIPRatio(nwid_begin->u.pip.pre, nwid_begin->u.pip.inter, nwid_begin->u.pip.post);
+
+				if (unlikely(nwc == nullptr && nwb == nullptr)) throw std::runtime_error("WPT_PIPRATIO requires NWidgetPIPContainer or NWidgetBackground");
 				break;
 			}