diff --git a/modules/lock/LockSurface.qml b/modules/lock/LockSurface.qml
index 81b577e..f360887 100644
--- a/modules/lock/LockSurface.qml
+++ b/modules/lock/LockSurface.qml
@@ -152,7 +152,8 @@ WlSessionLockSurface {
         cursorVisible: false
         enabled: !root._unlocking && root.auth.state !== "max" && root.auth.state !== "busy"
 
-        onTextChanged: root.auth.buffer = text
+        onTextChanged: if (root.auth)
+            root.auth.buffer = text
 
         Keys.onReturnPressed: root.auth.submit()
         Keys.onEnterPressed: root.auth.submit()