diff -r 1a786201465f -r efaae97bd95b ui/motif/button.c
--- a/ui/motif/button.c	Sun Nov 29 21:43:03 2015 +0100
+++ b/ui/motif/button.c	Mon Nov 30 14:09:55 2015 +0100
@@ -54,7 +54,7 @@
                 obj->ctx->mempool,
                 sizeof(UiEventData));
         event->obj = obj;
-        event->user_data = data;
+        event->userdata = data;
         event->callback = f;
         event->value = 0;
         XtAddCallback(
@@ -94,7 +94,7 @@
     e.window = event->obj->window;
     // TODO: e.document
     e.intval = tb->set;
-    event->callback(&e, event->user_data); 
+    event->callback(&e, event->userdata); 
 }
 
 void ui_push_button_callback(Widget widget, UiEventData *event, XtPointer d) {
@@ -103,5 +103,5 @@
     e.window = event->obj->window;
     e.document = event->obj->ctx->document;
     e.intval = event->value;
-    event->callback(&e, event->user_data);
+    event->callback(&e, event->userdata);
 }