diff --git a/testcases/t/529-net-wm-desktop.t b/testcases/t/529-net-wm-desktop.t
index 8f2df735..42b488d9 100644
--- a/testcases/t/529-net-wm-desktop.t
+++ b/testcases/t/529-net-wm-desktop.t
@@ -66,8 +66,15 @@ sub open_window_with_net_wm_desktop {
                 pack('L', $idx),
             );
         },
+	dont_map => 1,
     );
 
+    # We don’t wait for MapNotify and instead sync with i3 so that we don’t need
+    # to encounter the full timeout of 4s when opening a window on a non-visible
+    # workspace.
+    $window->map;
+    sync_with_i3;
+
     return $window;
 }
 
@@ -80,9 +87,7 @@ sub kill_windows {
 
 ###############################################################################
 
-my ($config, $config_mm, $pid, $con);
-
-$config = <<EOT;
+my $config = <<EOT;
 # i3 config file (v4)
 font -misc-fixed-medium-r-normal--13-120-75-75-C-70-iso10646-1
 
@@ -91,42 +96,25 @@ bar {
 }
 EOT
 
-$config_mm = <<EOT;
-# i3 config file (v4)
-font -misc-fixed-medium-r-normal--13-120-75-75-C-70-iso10646-1
-
-workspace "0" output "fake-0"
-workspace "1" output "fake-0"
-workspace "2" output "fake-0"
-workspace "10" output "fake-1"
-workspace "11" output "fake-1"
-workspace "12" output "fake-1"
-
-fake-outputs 1024x768+0+0,1024x768+1024+0
-EOT
+my $pid = launch_with_config($config);
 
 ###############################################################################
 # Upon managing a window which does not set _NET_WM_DESKTOP, the property is
 # set on the window.
 ###############################################################################
 
-$pid = launch_with_config($config);
-
 cmd 'workspace 1';
-$con = open_window;
+my $con = open_window;
 
 is(get_net_wm_desktop($con), 0, '_NET_WM_DESKTOP is set upon managing a window');
 
 kill_windows;
-exit_gracefully($pid);
 
 ###############################################################################
 # Upon managing a window which sets _NET_WM_DESKTOP, the window is moved to
 # the specified desktop.
 ###############################################################################
 
-$pid = launch_with_config($config);
-
 cmd 'workspace 0';
 open_window;
 cmd 'workspace 1';
@@ -140,15 +128,12 @@ is(get_net_wm_desktop($con), 1, '_NET_WM_DESKTOP still has the correct value');
 is_num_children('1', 2, 'The window was moved to workspace 1');
 
 kill_windows;
-exit_gracefully($pid);
 
 ###############################################################################
 # Upon managing a window which sets _NET_WM_DESKTOP to the appropriate value,
 # the window is made sticky and floating.
 ###############################################################################
 
-$pid = launch_with_config($config);
-
 cmd 'workspace 0';
 $con = open_window_with_net_wm_desktop(0xFFFFFFFF);
 
@@ -157,15 +142,12 @@ is(@{get_ws('0')->{floating_nodes}}, 1, 'The window is floating');
 ok(get_ws('0')->{floating_nodes}->[0]->{nodes}->[0]->{sticky}, 'The window is sticky');
 
 kill_windows;
-exit_gracefully($pid);
 
 ###############################################################################
 # _NET_WM_DESKTOP is updated when the window is moved to another workspace
 # on the same output.
 ###############################################################################
 
-$pid = launch_with_config($config);
-
 cmd 'workspace 0';
 open_window;
 cmd 'workspace 1';
@@ -178,15 +160,12 @@ cmd 'move window to workspace 1';
 is(get_net_wm_desktop($con), 1, '_NET_WM_DESKTOP is updated when moving the window');
 
 kill_windows;
-exit_gracefully($pid);
 
 ###############################################################################
 # _NET_WM_DESKTOP is updated when the floating window is moved to another
 # workspace on the same output.
 ###############################################################################
 
-$pid = launch_with_config($config);
-
 cmd 'workspace 0';
 open_window;
 cmd 'workspace 1';
@@ -200,35 +179,11 @@ cmd 'move window to workspace 1';
 is(get_net_wm_desktop($con), 1, '_NET_WM_DESKTOP is updated when moving the window');
 
 kill_windows;
-exit_gracefully($pid);
-
-###############################################################################
-# _NET_WM_DESKTOP is updated when the window is moved to another workspace
-# on another output.
-###############################################################################
-
-$pid = launch_with_config($config_mm);
-
-cmd 'workspace 0';
-open_window;
-cmd 'workspace 10';
-open_window;
-cmd 'workspace 0';
-$con = open_window;
-
-cmd 'move window to workspace 10';
-
-is(get_net_wm_desktop($con), 1, '_NET_WM_DESKTOP is updated when moving the window');
-
-kill_windows;
-exit_gracefully($pid);
 
 ###############################################################################
 # _NET_WM_DESKTOP is removed when the window is withdrawn.
 ###############################################################################
 
-$pid = launch_with_config($config);
-
 $con = open_window;
 is(get_net_wm_desktop($con), 0, '_NET_WM_DESKTOP is set (sanity check)');
 
@@ -238,15 +193,12 @@ wait_for_unmap($con);
 is(get_net_wm_desktop($con), undef, '_NET_WM_DESKTOP is removed');
 
 kill_windows;
-exit_gracefully($pid);
 
 ###############################################################################
 # A _NET_WM_DESKTOP client message sent to the root window moves a window
 # to the correct workspace.
 ###############################################################################
 
-$pid = launch_with_config($config);
-
 cmd 'workspace 0';
 open_window;
 cmd 'workspace 1';
@@ -263,15 +215,12 @@ is_num_children('1', 2, 'The window is now on workspace 1');
 is(get_net_wm_desktop($con), 1, '_NET_WM_DESKTOP is updated');
 
 kill_windows;
-exit_gracefully($pid);
 
 ###############################################################################
 # A _NET_WM_DESKTOP client message sent to the root window can make a window
 # sticky.
 ###############################################################################
 
-$pid = launch_with_config($config);
-
 cmd 'workspace 0';
 $con = open_window;
 
@@ -282,15 +231,12 @@ is(@{get_ws('0')->{floating_nodes}}, 1, 'The window is floating');
 ok(get_ws('0')->{floating_nodes}->[0]->{nodes}->[0]->{sticky}, 'The window is sticky');
 
 kill_windows;
-exit_gracefully($pid);
 
 ###############################################################################
 # _NET_WM_DESKTOP is updated when a new workspace with a lower number is
 # opened and closed.
 ###############################################################################
 
-$pid = launch_with_config($config);
-
 cmd 'workspace 1';
 $con = open_window;
 is(get_net_wm_desktop($con), 0, '_NET_WM_DESKTOP is set sanity check)');
@@ -299,14 +245,11 @@ cmd 'workspace 0';
 is(get_net_wm_desktop($con), 1, '_NET_WM_DESKTOP is updated');
 
 kill_windows;
-exit_gracefully($pid);
 
 ###############################################################################
 # _NET_WM_DESKTOP is updated when a window is made sticky by command.
 ###############################################################################
 
-$pid = launch_with_config($config);
-
 cmd 'workspace 0';
 $con = open_window;
 cmd 'floating enable';
@@ -316,14 +259,11 @@ cmd 'sticky enable';
 is(get_net_wm_desktop($con), 0xFFFFFFFF, '_NET_WM_DESKTOP is updated');
 
 kill_windows;
-exit_gracefully($pid);
 
 ###############################################################################
 # _NET_WM_DESKTOP is updated when a window is made sticky by client message.
 ###############################################################################
 
-$pid = launch_with_config($config);
-
 cmd 'workspace 0';
 $con = open_window;
 cmd 'floating enable';
@@ -343,14 +283,11 @@ sync_with_i3;
 is(get_net_wm_desktop($con), 0xFFFFFFFF, '_NET_WM_DESKTOP is updated');
 
 kill_windows;
-exit_gracefully($pid);
 
 ###############################################################################
 # _NET_WM_DESKTOP is updated when a window is moved to the scratchpad.
 ###############################################################################
 
-$pid = launch_with_config($config);
-
 cmd 'workspace 0';
 $con = open_window;
 cmd 'floating enable';
@@ -363,8 +300,9 @@ cmd 'scratchpad show';
 is(get_net_wm_desktop($con), 0, '_NET_WM_DESKTOP is set sanity check)');
 
 kill_windows;
-exit_gracefully($pid);
 
 ###############################################################################
 
+exit_gracefully($pid);
+
 done_testing;
diff --git a/testcases/t/529-net-wm-desktop_mm.t b/testcases/t/529-net-wm-desktop_mm.t
new file mode 100644
index 00000000..77238946
--- /dev/null
+++ b/testcases/t/529-net-wm-desktop_mm.t
@@ -0,0 +1,75 @@
+#!perl
+# vim:ts=4:sw=4:expandtab
+#
+# Please read the following documents before working on tests:
+# • http://build.i3wm.org/docs/testsuite.html
+#   (or docs/testsuite)
+#
+# • http://build.i3wm.org/docs/lib-i3test.html
+#   (alternatively: perldoc ./testcases/lib/i3test.pm)
+#
+# • http://build.i3wm.org/docs/ipc.html
+#   (or docs/ipc)
+#
+# • http://onyxneon.com/books/modern_perl/modern_perl_a4.pdf
+#   (unless you are already familiar with Perl)
+#
+# Tests for _NET_WM_DESKTOP.
+# Ticket: #2153
+use i3test i3_autostart => 0;
+use X11::XCB qw(:all);
+
+sub get_net_wm_desktop {
+    sync_with_i3;
+
+    my ($con) = @_;
+    my $cookie = $x->get_property(
+        0,
+        $con->{id},
+        $x->atom(name => '_NET_WM_DESKTOP')->id,
+        $x->atom(name => 'CARDINAL')->id,
+        0,
+        1
+    );
+
+    my $reply = $x->get_property_reply($cookie->{sequence});
+    return undef if $reply->{length} != 1;
+
+    return unpack("L", $reply->{value});
+}
+
+my $config = <<EOT;
+# i3 config file (v4)
+font -misc-fixed-medium-r-normal--13-120-75-75-C-70-iso10646-1
+
+workspace "0" output "fake-0"
+workspace "1" output "fake-0"
+workspace "2" output "fake-0"
+workspace "10" output "fake-1"
+workspace "11" output "fake-1"
+workspace "12" output "fake-1"
+
+fake-outputs 1024x768+0+0,1024x768+1024+0
+EOT
+
+###############################################################################
+# _NET_WM_DESKTOP is updated when the window is moved to another workspace
+# on another output.
+###############################################################################
+
+my $pid = launch_with_config($config);
+
+cmd 'workspace 0';
+open_window;
+cmd 'workspace 10';
+open_window;
+cmd 'workspace 0';
+my $con = open_window;
+
+cmd 'move window to workspace 10';
+
+is(get_net_wm_desktop($con), 1, '_NET_WM_DESKTOP is updated when moving the window');
+
+exit_gracefully($pid);
+
+done_testing;