diff --git a/contrib/pyln-client/pyln/client/lightning.py b/contrib/pyln-client/pyln/client/lightning.py
index 8dc39f611..951cca349 100644
--- a/contrib/pyln-client/pyln/client/lightning.py
+++ b/contrib/pyln-client/pyln/client/lightning.py
@@ -515,7 +515,8 @@ class LightningRpc(UnixDomainSocketRpc):
         payload.update({k: v for k, v in kwargs.items()})
         return self.call("check", payload)
 
-    def close(self, peer_id, unilateraltimeout=None, destination=None, fee_negotiation_step=None, force_lease_closed=False):
+    def close(self, peer_id, unilateraltimeout=None, destination=None,
+              fee_negotiation_step=None, force_lease_closed=None):
         """
         Close the channel with peer {id}, forcing a unilateral
         close after {unilateraltimeout} seconds if non-zero, and