diff --git a/src/gd_sophia_editor.erl b/src/gd_sophia_editor.erl
index ee9a7a3..03b62ed 100644
--- a/src/gd_sophia_editor.erl
+++ b/src/gd_sophia_editor.erl
@@ -97,6 +97,8 @@ new(Parent) ->
                       [{face, "Monospace"}]),
     SetMonospace = fun(Style) -> wxStyledTextCtrl:styleSetFont(STC, Style, Mono) end,
     ok = lists:foreach(SetMonospace, styles()),
+    ok = wxStyledTextCtrl:setMarginType(STC, 0, ?wxSTC_MARGIN_NUMBER),
+    ok = wxStyledTextCtrl:setMarginWidth(STC, 0, 40),
     ok = wxStyledTextCtrl:styleSetFont(STC, ?wxSTC_STYLE_DEFAULT, Mono),
     ok = set_colors(STC),
     STC.