diff --git a/modules/lock/LockSurface.qml b/modules/lock/LockSurface.qml
index a05e689c..279c5513 100644
--- a/modules/lock/LockSurface.qml
+++ b/modules/lock/LockSurface.qml
@@ -144,14 +144,14 @@ WlSessionLockSurface {
                 Anim {
                     target: lockContent
                     property: "implicitWidth"
-                    to: root.screen.height * Config.lock.sizes.heightMult * Config.lock.sizes.ratio
+                    to: (root.screen?.height ?? 0) * Config.lock.sizes.heightMult * Config.lock.sizes.ratio
                     duration: Appearance.anim.durations.expressiveDefaultSpatial
                     easing.bezierCurve: Appearance.anim.curves.expressiveDefaultSpatial
                 }
                 Anim {
                     target: lockContent
                     property: "implicitHeight"
-                    to: root.screen.height * Config.lock.sizes.heightMult
+                    to: (root.screen?.height ?? 0) * Config.lock.sizes.heightMult
                     duration: Appearance.anim.durations.expressiveDefaultSpatial
                     easing.bezierCurve: Appearance.anim.curves.expressiveDefaultSpatial
                 }