diff --git a/libs/blockview/blockbusitem.cpp b/libs/blockview/blockbusitem.cpp
index 29d5d7f..a22e413 100644
--- a/libs/blockview/blockbusitem.cpp
+++ b/libs/blockview/blockbusitem.cpp
@@ -304,6 +304,14 @@ void BlockBusItem::simplify(bool full) {
 }
 
 
+bool BlockBusItem::hasNullSegment() const {
+	for (int s = 0; s < segments.size(); ++s) {
+		if (pol[segments[s].first] == pol[segments[s].second]) return true;
+	}
+	return false;
+}
+
+
 void BlockBusItem::adjustLine() {}
 
 
diff --git a/libs/blockview/blockbusitem.h b/libs/blockview/blockbusitem.h
index 7a5d409..ac781a0 100644
--- a/libs/blockview/blockbusitem.h
+++ b/libs/blockview/blockbusitem.h
@@ -91,6 +91,7 @@ public:
 	void markAsOutput();
 	void unmark();
 	void simplify(bool full = true);
+	bool hasNullSegment() const;
 	void adjustLine();
 	int endpointCount() const;
 	bool isBusSelected() const { return selSegment >= 0 || selPoint >= 0; }
diff --git a/libs/blockview/blockview.cpp b/libs/blockview/blockview.cpp
index cc343ef..8af8435 100644
--- a/libs/blockview/blockview.cpp
+++ b/libs/blockview/blockview.cpp
@@ -464,9 +464,14 @@ bool BlockView::eventFilter(QObject * o, QEvent * e) {
 						}
 						if (!mm_mods.testFlag(Qt::ControlModifier) && !mm_mods.testFlag(Qt::ShiftModifier)) {
 							if (!mdp.isNull()) moved = true;
-							foreach(QGraphicsItem * i, sel_items)
-								if (i->flags().testFlag(QGraphicsItem::ItemIsMovable)) i->setPos(i->pos() + mdp);
-							if (!me->modifiers().testFlag(Qt::AltModifier)) moveBuses(sel_items, mdp);
+							bool is_correct = true;
+							if (!me->modifiers().testFlag(Qt::AltModifier)) is_correct = moveBuses(sel_items, mdp);
+							if (is_correct) {
+								for (auto * i: sel_items)
+									if (i->flags().testFlag(QGraphicsItem::ItemIsMovable)) i->setPos(i->pos() + mdp);
+							} else {
+								scene_point -= mdp;
+							}
 							setCursor(Qt::ClosedHandCursor);
 						}
 						return true;
@@ -1487,28 +1492,42 @@ void BlockView::simplifyBuses() {
 }
 
 
-void BlockView::moveBuses(const QList<QGraphicsItem *> & items, QPointF dp) {
-	if (dp.isNull()) return;
+bool BlockView::moveBuses(const QList<QGraphicsItem *> & items, QPointF dp) {
+	if (dp.isNull()) return true;
 	QList<QGraphicsItem *> gi = scene_->items();
 	QVector<BlockItemPin *> pins;
-	QList<BlockBusItem *> buses;
+	QList<BlockBusItem *> buses_m_part, buses_m_all;
+	QMap<BlockBusItem *, QPolygonF> saved_pols;
 	// qDebug() << "move" << dp;
-	foreach(QGraphicsItem * i, items)
+	for (auto * i: items)
 		if ((i->data(bvidType).toInt() == bvitBlock) && i->flags().testFlag(QGraphicsItem::ItemIsMovable))
 			pins << qgraphicsitem_cast<BlockItem *>(i)->pins();
-	foreach(QGraphicsItem * i, gi)
-		if (i->data(bvidType).toInt() == bvitBus) buses << qgraphicsitem_cast<BlockBusItem *>(i);
-	foreach(BlockBusItem * b, buses) {
-		QList<BlockItemPin *> bpins = b->connections_.values();
-		if (!bpins.isEmpty()) {
-			foreach(BlockItemPin * p, pins)
+	for (auto * i: gi) {
+		if (i->data(bvidType).toInt() == bvitBus) {
+			auto * b                    = qgraphicsitem_cast<BlockBusItem *>(i);
+			QList<BlockItemPin *> bpins = b->connectedPins();
+			if (bpins.isEmpty()) continue;
+			bool affect = false;
+			for (auto * i: pins) {
+				if (bpins.contains(i)) {
+					affect = true;
+					break;
+				}
+			}
+			if (!affect) continue;
+			for (auto * p: pins)
 				bpins.removeAll(p);
-			if (bpins.isEmpty()) {
-				b->movePolyline(dp);
-				continue;
+			if (bpins.isEmpty())
+				buses_m_all << b;
+			else {
+				buses_m_part << b;
+				saved_pols[b] = b->pol;
 			}
 		}
-		foreach(BlockItemPin * p, pins) {
+	}
+	bool incorrect_move = false;
+	for (auto * b: buses_m_part) {
+		for (auto * p: pins) {
 			QList<int> ends = b->connections_.keys(p);
 			for (int i = 0; i < ends.size(); ++i) {
 				QPointF pdp = dp;
@@ -1533,12 +1552,26 @@ void BlockView::moveBuses(const QList<QGraphicsItem *> & items, QPointF dp) {
 				default: break;
 				}
 				QVector<int> epl = b->endpointLine(ends[i], ang);
-				foreach(int e, epl)
+				for (int e: epl)
 					b->movePoint(e, pdp);
 				b->movePoint(ends[i], dp);
+				if (b->hasNullSegment()) {
+					incorrect_move = true;
+					break;
+				}
 			}
+			if (incorrect_move) break;
 		}
+		if (incorrect_move) break;
 	}
+	if (incorrect_move) {
+		for (auto * b: buses_m_part)
+			b->pol = saved_pols.value(b);
+		return false;
+	}
+	for (auto * b: buses_m_all)
+		b->movePolyline(dp);
+	return true;
 }
 
 
diff --git a/libs/blockview/blockview.h b/libs/blockview/blockview.h
index f902abd..cd80438 100644
--- a/libs/blockview/blockview.h
+++ b/libs/blockview/blockview.h
@@ -158,7 +158,7 @@ protected:
 	void hoverAcceptedPin(BlockItemPin * pin, bool hover);
 	void unhoverPins(BlockItemPin * excl_pin = 0);
 	void simplifyBuses();
-	void moveBuses(const QList<QGraphicsItem *> & items, QPointF dp);
+	bool moveBuses(const QList<QGraphicsItem *> & items, QPointF dp);
 	QList<BlockBusItem *> internalBuses(const QList<BlockItem *> & items);
 	QList<BlockItemPin *> nearPins(BlockItemPin * pin, Qt::KeyboardModifiers km);
 	BlockItemPin * getPin(const QList<QGraphicsItem *> & list) const;