diff --git a/hw/xwayland/xwayland-input.c b/hw/xwayland/xwayland-input.c
index fbb6b6b2c..45acf0c97 100644
--- a/hw/xwayland/xwayland-input.c
+++ b/hw/xwayland/xwayland-input.c
@@ -103,7 +103,7 @@ xwl_pointer_proc(DeviceIntPtr device, int what)
         if (!InitPtrFeedbackClassDeviceStruct(device, xwl_pointer_control))
             return BadValue;
 
-        if (!InitButtonClassDeviceStruct(device, 3, btn_labels, map))
+        if (!InitButtonClassDeviceStruct(device, NBUTTONS, btn_labels, map))
             return BadValue;
 
         return Success;