diff --git a/src/main.cpp b/src/main.cpp
index 42ff3958b4..65c71b9ea5 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -381,6 +381,7 @@ static X11EventFilterContainer *takeEventFilter(X11EventFilter *eventFilter,
 
 void Application::setXwaylandScale(qreal scale)
 {
+    Q_ASSERT(scale != 0);
     if (scale != m_xwaylandScale) {
         m_xwaylandScale = scale;
         // change the font dpi to match
diff --git a/src/wayland/clientconnection.cpp b/src/wayland/clientconnection.cpp
index dcd839f4a8..98e6382f0b 100644
--- a/src/wayland/clientconnection.cpp
+++ b/src/wayland/clientconnection.cpp
@@ -155,6 +155,7 @@ QString ClientConnection::executablePath() const
 
 void ClientConnection::setScaleOverride(qreal scaleOveride)
 {
+    Q_ASSERT(scaleOveride != 0);
     d->scaleOverride = scaleOveride;
     Q_EMIT scaleOverrideChanged();
 }
diff --git a/src/workspace.cpp b/src/workspace.cpp
index ae7e8208db..e1ed446dfa 100644
--- a/src/workspace.cpp
+++ b/src/workspace.cpp
@@ -477,7 +477,7 @@ bool Workspace::applyOutputConfiguration(const OutputConfiguration &config, cons
     KConfig cfg(QStringLiteral("kdeglobals"));
     KConfigGroup kscreenGroup = cfg.group("KScreen");
     const bool xwaylandClientsScale = kscreenGroup.readEntry("XwaylandClientsScale", true);
-    if (xwaylandClientsScale) {
+    if (xwaylandClientsScale && !outputOrder.isEmpty()) {
         double maxScale = 0;
         for (Output *output : outputOrder) {
             const auto changeset = config.constChangeSet(output);