diff --git a/src/saveload/autoreplace_sl.cpp b/src/saveload/autoreplace_sl.cpp
--- a/src/saveload/autoreplace_sl.cpp
+++ b/src/saveload/autoreplace_sl.cpp
@@ -20,6 +20,7 @@ static const SaveLoad _engine_renew_desc
 
 	    SLE_REF(EngineRenew, next,     REF_ENGINE_RENEWS),
 	SLE_CONDVAR(EngineRenew, group_id, SLE_UINT16, 60, SL_MAX_VERSION),
+	SLE_CONDVAR(EngineRenew, replace_when_old, SLE_BOOL, 175, SL_MAX_VERSION),
 	SLE_END()
 };