diff --git a/src/app/MetaBrush/Document/Selection.hs b/src/app/MetaBrush/Document/Selection.hs
index 80c5e4d..a6eb58f 100644
--- a/src/app/MetaBrush/Document/Selection.hs
+++ b/src/app/MetaBrush/Document/Selection.hs
@@ -92,7 +92,7 @@ instance Monoid SelectionMode where
 selectionMode :: Foldable f => f Modifier -> SelectionMode
 selectionMode = foldMap \case
   Alt   _ -> Subtract
-  Shift _ -> Subtract
+  Shift _ -> Add
   _       -> New
 
 -- | Updates the selected objects on a single click selection event.