diff --git a/openvpn.py b/openvpn.py
index 2c07705..e484f1e 100644
--- a/openvpn.py
+++ b/openvpn.py
@@ -281,7 +281,7 @@ class Openvpn:
             logging.debug(f"interface {self.interface} is not ready.")
             return
 
-        self.monitor_interval = True
+        self.interface_up = True
         io_count = io_count[self.interface]
         open(self.io_stat_fp, "a").write(
             f"{datetime.utcnow().timestamp()},{io_count.bytes_recv},{io_count.bytes_sent}\n")