diff --git a/qad/blockview/blockview.cpp b/qad/blockview/blockview.cpp
index 77173c4..e962989 100644
--- a/qad/blockview/blockview.cpp
+++ b/qad/blockview/blockview.cpp
@@ -1299,6 +1299,7 @@ QList<BlockBusItem * > BlockView::internalBuses(const QList<BlockItem * > & item
 	QList<BlockBusItem * > sbl = buses();
 	QSet<BlockItem * > sis = QSet<BlockItem * >::fromList(items);
 	foreach (BlockBusItem * bi, sbl) {
+		if (bi->connectedBlocks().isEmpty()) continue;
 		QSet<BlockItem * > bis = QSet<BlockItem * >::fromList(bi->connectedBlocks());
 		if ((bis - sis).isEmpty())
 			ret << bi;