diff --git a/dronekit/mavlink.py b/dronekit/mavlink.py
index d87f93ae5..ae231bcb2 100644
--- a/dronekit/mavlink.py
+++ b/dronekit/mavlink.py
@@ -281,7 +281,7 @@ def reset(self):
 
     def fix_targets(self, message):
         """Set correct target IDs for our vehicle"""
-        if hasattr(message, 'target_system'):
+        if hasattr(message, 'target_system') and message.target_system < 0:
             message.target_system = self.target_system
 
     def forward_loop(self, fn):