Downgrade warning dialog is visually broken #5325

diff --git a/source/gui/installerGui.py b/source/gui/installerGui.py
index 8438921..4ddb712 100644
--- a/source/gui/installerGui.py
+++ b/source/gui/installerGui.py
@@ -161,8 +161,11 @@ def showInstallGui():
            # Translators: The label of a button to proceed with installation,
            # even though this is not recommended.
            label=_("&Proceed with installation (not recommended)"))
+       sizer.Add(item)
        item = wx.Button(d, id=wx.ID_CANCEL)
        item.SetFocus()
+       sizer.Add(item)
+       mainSizer.Add(sizer)
        d.Sizer = mainSizer
        mainSizer.Fit(d)
        d.Center(wx.BOTH | wx.CENTER_ON_SCREEN)