diff --git a/testcases/t/14-client-leader.t b/testcases/t/14-client-leader.t
new file mode 100644
index 00000000..ead52764
--- /dev/null
+++ b/testcases/t/14-client-leader.t
@@ -0,0 +1,72 @@
+#!perl
+# vim:ts=4:sw=4:expandtab
+# Beware that this test uses workspace 9 and 10 to perform some tests (it expects
+# the workspace to be empty).
+# TODO: skip it by default?
+
+use Test::More tests => 5;
+use Test::Deep;
+use X11::XCB qw(:all);
+use Data::Dumper;
+use Time::HiRes qw(sleep);
+use FindBin;
+use Digest::SHA1 qw(sha1_base64);
+use lib "$FindBin::Bin/lib";
+use i3test;
+
+BEGIN {
+    use_ok('IO::Socket::UNIX') or BAIL_OUT('Cannot load IO::Socket::UNIX');
+    use_ok('X11::XCB::Connection') or BAIL_OUT('Cannot load X11::XCB::Connection');
+}
+
+my $x = X11::XCB::Connection->new;
+
+my $sock = IO::Socket::UNIX->new(Peer => '/tmp/i3-ipc.sock');
+isa_ok($sock, 'IO::Socket::UNIX');
+
+# Switch to the nineth workspace
+$sock->write(i3test::format_ipc_command("9"));
+
+sleep 0.25;
+
+#####################################################################
+# Create a parent window
+#####################################################################
+
+my $window = $x->root->create_child(
+class => WINDOW_CLASS_INPUT_OUTPUT,
+rect => [ 0, 0, 30, 30 ],
+background_color => '#C0C0C0',
+);
+
+$window->name('Parent window');
+$window->map;
+
+sleep 0.25;
+
+#########################################################################
+# Switch workspace to 10 and open a child window. It should be positioned
+# on workspace 9.
+#########################################################################
+$sock->write(i3test::format_ipc_command("10"));
+sleep 0.25;
+
+my $child = $x->root->create_child(
+class => WINDOW_CLASS_INPUT_OUTPUT,
+rect => [ 0, 0, 30, 30 ],
+background_color => '#C0C0C0',
+);
+
+$child->name('Child window');
+$child->client_leader($window);
+$child->map;
+
+sleep 0.25;
+
+isnt($x->input_focus, $child->id, "Child window focused");
+
+# Switch back
+$sock->write(i3test::format_ipc_command("9"));
+sleep 0.25;
+
+is($x->input_focus, $child->id, "Child window focused");