diff --git a/Canvas.cpp b/Canvas.cpp
index b0b61dc..1da4204 100644
--- a/Canvas.cpp
+++ b/Canvas.cpp
@@ -218,7 +218,7 @@ void Canvas::mousePressEvent(QMouseEvent* event)
 		if (l1 == l2 && l1 && l2 ||
 			(areCoincident(firstPoint, clickedPoint))) 
 		{
-			QMessageBox::warning(this, QString("NO!"), QString("P2P failed"));
+			QMessageBox::critical(this, QString("NO!"), QString("P2P failed"));
 			firstPoint = nullptr;
 			mode = Mode::None;
 			update();
@@ -271,7 +271,7 @@ void Canvas::paintEvent(QPaintEvent*)
 			sys.applySolution();
 		}
 		else if (res == SolveStatus::Failed && after_constraint){
-			QMessageBox::warning(this, QString("Error!"), QString("Last constraint is unavailable!"));
+			QMessageBox::critical(this, QString("Error!"), QString("Last constraint is unavailable!"));
 			sys.removeConstraint(sys.get_last_constraint());
 			constraints_count--;
 		}