diff --git a/kippo/core/output.py b/kippo/core/output.py
index 78dd056b..a1a6ff64 100644
--- a/kippo/core/output.py
+++ b/kippo/core/output.py
@@ -105,6 +105,7 @@ class Output(object):
             return
 
         ev = copy.copy(event)
+        del ev['isError']
 
         # add ISO timestamp and sensor data
         if not 'time' in ev: