diff --git a/share/grafx2/gfx2def.ini b/share/grafx2/gfx2def.ini
index 99bec840..b05c8ef8 100644
--- a/share/grafx2/gfx2def.ini
+++ b/share/grafx2/gfx2def.ini
@@ -366,4 +366,12 @@
   ; the same dimensions.
   Sync_views = YES; (Default YES)
     
+  ; This setting determines which key inverts the mouse buttons
+  ; when it's held : A left click is then interpreted as a right-click.
+  ; It's especially useful for one-button controllers,
+  ; such as touchscreens and tablets.
+  ; Possible values are 0 (none), 1 (control), 2 (alt)
+    
+  Swap_buttons = 1; (Default 1)
+  
   ; end of configuration