diff --git a/alb-s3-sqs-es/alb_s3/ingester/message.py b/alb-s3-sqs-es/alb_s3/ingester/message.py
index 313098c..5ceea73 100644
--- a/alb-s3-sqs-es/alb_s3/ingester/message.py
+++ b/alb-s3-sqs-es/alb_s3/ingester/message.py
@@ -69,7 +69,7 @@ def __init__(self, log_msg):
                     self.message["client_port"] = client_ip[-1]
 
             # Parse User-Agent string
-            if self.message["user_agent"] is not None:
+            if "user_agent" in self.message:
                 user_agent = parse(self.message["user_agent"])
                 user_agent_details = {}
                 user_agent_details["browser"] = user_agent.get_browser()