diff --git a/src/MainWindow.cpp b/src/MainWindow.cpp
index 0502886..0ba1f27 100644
--- a/src/MainWindow.cpp
+++ b/src/MainWindow.cpp
@@ -144,6 +144,7 @@ MainWindow::MainWindow(ApplicationController* appController, QWidget *parent)
 
     connect(m_viewport, &ViewportWidget::lineAdded, m_appController, &ApplicationController::addLine);
     connect(m_viewport, &ViewportWidget::planeSelected, m_appController, &ApplicationController::onPlaneSelected);
+    connect(m_viewport, &ViewportWidget::toolDeactivated, m_appController, [this]() { m_appController->setActiveTool(ApplicationController::ToolType::None); });
 
     updateWindowTitle(QString());
 }