1 files changed, 4 insertions, 3 deletions

diff --git a/python/webiopi/devices/sensor/icmp.py b/python/webiopi/devices/sensor/icmp.py
index 8a4065d..37028fa 100644
--- a/python/webiopi/devices/sensor/icmp.py
+++ b/python/webiopi/devices/sensor/icmp.py
@@ -36,7 +36,8 @@ class ICMP(Duration):
         return Duration.__family__(self)
 
     def __getMilliseconds__(self):
-        return self.echo(self.ip, 1) * 1000
+        sec = self.echo(self.ip, 1)
+        return sec * 1000 if sec > 0 else -1
 
     def close(self):
         pass
@@ -79,7 +80,7 @@ class ICMP(Duration):
         while True:
             ready = select.select([sock], [], [], timeout)
             if ready[0] == []:  # Timeout
-                return
+                return -1
 
             time_received = time()
             rec_packet, addr = sock.recvfrom(1024)
@@ -91,7 +92,7 @@ class ICMP(Duration):
 
             timeout -= time_received - time_sent
             if timeout <= 0:
-                return
+                return -1
 
     def echo(self, dest_addr, timeout=1):
         """