diff --git a/src/text_editor.cpp b/src/text_editor.cpp
index c49a98d..7e9d0fc 100644
--- a/src/text_editor.cpp
+++ b/src/text_editor.cpp
@@ -315,9 +315,30 @@ void OnCommand(Event event) {
             }
         }
 
-    Int p = ScreenSpaceToBufferPos(selected.window, selected.view, selected.buffer, mouse);
+        Int p = ScreenSpaceToBufferPos(selected.window, selected.view, selected.buffer, mouse);
         Caret &caret = selected.view->carets[0];
         caret = SetFrontWithAnchor(caret, DocumentAnchor, p);
+
+        if (event.alt && event.shift) {
+            Int front = GetFront(DocumentAnchor);
+            XY from = PosToXY(selected.buffer, front);
+            XY to = ScreenSpaceToXY(selected.window, selected.view, mouse);
+            Int min_line = Min(from.y, to.y);
+            Int max_line = Max(from.y, to.y);
+            Int min_col = Min(from.x, to.x);
+            Int max_col = Max(from.x, to.x);
+
+            selected.view->carets.len = 0;
+            for (Int line = min_line; line <= max_line; line += 1) {
+                XY left_xy = {min_col, line};
+                XY right_xy = {max_col, line};
+                Int left = XYToPosWithoutNL(selected.buffer, left_xy);
+                Int right = XYToPosWithoutNL(selected.buffer, right_xy);
+                Caret new_selection = MakeCaret(left, right);
+                Add(&selected.view->carets, new_selection);
+            }
+            MergeCarets(selected.buffer, &selected.view->carets);
+        }
     }
 
     if (ResizerSelected.id != -1 && Mouse(LEFT_UP)) {