diff --git a/src/desktop/view/Window.cpp b/src/desktop/view/Window.cpp
index 5d414c49..ea2b9526 100644
--- a/src/desktop/view/Window.cpp
+++ b/src/desktop/view/Window.cpp
@@ -1953,6 +1953,7 @@ void CWindow::mapWindow() {
         && Desktop::focusState()->window()->m_workspace == m_workspace                     // workspaces match, we're not opening on another ws
         && !g_pXWaylandManager->shouldBeFloated(m_self.lock()) && !isX11OverrideRedirect() // not a window that should float or X11
         && !(m_isFloating && !Desktop::focusState()->window()->m_isFloating)               // do not auto-group a floated window into a tiled group
+        && !isModal()                                                                      // no modal grouping
     ) {
         // add to group if we are focused on one
         Desktop::focusState()->window()->m_group->add(m_self.lock());