diff --git a/invesalius/gui/bitmap_preview_panel.py b/invesalius/gui/bitmap_preview_panel.py
index e66432a..18f0c9a 100644
--- a/invesalius/gui/bitmap_preview_panel.py
+++ b/invesalius/gui/bitmap_preview_panel.py
@@ -229,7 +229,7 @@ class Preview(wx.Panel):
     def OnSelect(self, evt):
 
         shift_pressed = False
-        if evt.m_shiftDown:
+        if evt.shiftDown:
             shift_pressed = True
 
         self.select_on = True
diff --git a/invesalius/gui/dicom_preview_panel.py b/invesalius/gui/dicom_preview_panel.py
index 52d2326..7679a66 100644
--- a/invesalius/gui/dicom_preview_panel.py
+++ b/invesalius/gui/dicom_preview_panel.py
@@ -280,7 +280,7 @@ class Preview(wx.Panel):
     def OnSelect(self, evt):
 
         shift_pressed = False
-        if evt.m_shiftDown:
+        if evt.shiftDown:
             shift_pressed = True
 
         dicom_id = self.dicom_info.id
--
libgit2 0.21.2