diff --git a/tradedb.py b/tradedb.py
index 2e8dddbb..7620a987 100644
--- a/tradedb.py
+++ b/tradedb.py
@@ -801,6 +801,8 @@ def addLocalSystem(
             "Added new system #{}: {} [{},{},{}]",
             ID, name, x, y, z
         )
+        # Invalidate the grid
+        self.stellarGrid = None
         return system
 
     def updateLocalSystem(