diff --git a/sc2reader/engine/plugins/context.py b/sc2reader/engine/plugins/context.py
index dd846634..74e7c548 100644
--- a/sc2reader/engine/plugins/context.py
+++ b/sc2reader/engine/plugins/context.py
@@ -250,7 +250,7 @@ def handleUnitOwnerChangeEvent(self, event, replay):
                 )
             )
 
-        if event.unit_upkeeper:
+        if event.unit_upkeeper and event.unit:
             if event.unit.owner:
                 event.unit.owner.units.remove(event.unit)
             event.unit.owner = event.unit_upkeeper