diff --git a/xpra/x11/x11_server_core.py b/xpra/x11/x11_server_core.py
index e42ae189fb..ccc826524b 100644
--- a/xpra/x11/x11_server_core.py
+++ b/xpra/x11/x11_server_core.py
@@ -203,7 +203,7 @@ def init_randr(self) -> None:
             sizes = RandR.get_xrr_screen_sizes()
             if len(sizes)==1:
                 self.randr_exact_size = True
-                prop_set(self.root_window, "_XPRA_RANDR_EXACT_SIZE", "u32", 1)
+                prop_set(xid, "_XPRA_RANDR_EXACT_SIZE", "u32", 1)
             elif not sizes:
                 #xwayland?
                 self.randr = False
@@ -321,7 +321,7 @@ def do_clean_x11_properties(self, *properties) -> None:
         root = get_default_root_window()
         for prop in properties:
             try:
-                prop_del(root, prop)
+                prop_del(root.get_xid(), prop)
             except Exception as e:
                 log("prop_del(%s, %s) %s", root, prop, e)