diff --git a/testcases/lib/i3test.pm b/testcases/lib/i3test.pm
index a6b982ba..212e78fd 100644
--- a/testcases/lib/i3test.pm
+++ b/testcases/lib/i3test.pm
@@ -337,6 +337,7 @@ sub open_window {
     $args{name} //= 'Window ' . counter_window();
 
     my $window = $x->root->create_child(%args);
+    $window->add_hint('input');
 
     if ($before_map) {
         # TODO: investigate why _create is not needed