diff --git a/ncclient/operations/rpc.py b/ncclient/operations/rpc.py
index 18b50484..d0d7f5cb 100644
--- a/ncclient/operations/rpc.py
+++ b/ncclient/operations/rpc.py
@@ -165,6 +165,7 @@ def xml(self):
     @property
     def ok(self):
         "Boolean value indicating if there were no errors."
+        self.parse()
         return not self.errors # empty list => false
 
     @property