diff --git a/common/utils/T/tracer/gui/x.c b/common/utils/T/tracer/gui/x.c
index 50164dce35..68869d6e0f 100644
--- a/common/utils/T/tracer/gui/x.c
+++ b/common/utils/T/tracer/gui/x.c
@@ -151,6 +151,7 @@ printf("x_events START\n");
     XNextEvent(x->d, &ev);
 printf("XEV %d\n", ev.type);
     switch (ev.type) {
+    case MapNotify:
     case Expose:
       if ((w = find_x_window(g, ev.xexpose.window)) != NULL) {
         struct x_window *xw = w->x;