diff --git a/src/item_location.cpp b/src/item_location.cpp
index 064a67b96166d..df322fa67ba59 100644
--- a/src/item_location.cpp
+++ b/src/item_location.cpp
@@ -433,6 +433,7 @@ class item_location::impl::item_on_vehicle : public item_location::impl
             } else {
                 cur.remove_item( *target() ); // item within CARGO
             }
+            cur.veh.invalidate_mass();
         }
 };