diff --git a/basis/x11/xlib/xlib.factor b/basis/x11/xlib/xlib.factor
index 7914c7cf1a..e20314bf11 100644
--- a/basis/x11/xlib/xlib.factor
+++ b/basis/x11/xlib/xlib.factor
@@ -565,7 +565,8 @@ CONSTANT: SelectionNotify       31
 CONSTANT: ColormapNotify        32
 CONSTANT: ClientMessage         33
 CONSTANT: MappingNotify         34
-CONSTANT: LASTEvent             35
+CONSTANT: GenericEvent          35
+CONSTANT: LASTEvent             36
 
 STRUCT: XAnyEvent
 { type int }