diff --git a/testcases/lib/i3test.pm b/testcases/lib/i3test.pm
index ad598b84..f5cb0602 100644
--- a/testcases/lib/i3test.pm
+++ b/testcases/lib/i3test.pm
@@ -39,6 +39,7 @@ our @EXPORT = qw(
     wait_for_event
     wait_for_map
     wait_for_unmap
+    $x
 );
 
 my $tester = Test::Builder->new();
@@ -46,6 +47,8 @@ my $_cached_socket_path = undef;
 my $_sync_window = undef;
 my $tmp_socket_path = undef;
 
+our $x;
+
 BEGIN {
     my $window_count = 0;
     sub counter_window {
@@ -72,6 +75,7 @@ __
     strict->import;
     warnings->import;
 
+    $x ||= i3test::X11->new;
     @_ = ($class);
     goto \&Exporter::import;
 }
@@ -404,7 +408,6 @@ sub get_socket_path {
         return $_cached_socket_path;
     }
 
-    my $x = X11::XCB::Connection->new;
     my $atom = $x->atom(name => 'I3_SOCKET_PATH');
     my $cookie = $x->get_property(0, $x->get_root_window(), $atom->id, GET_PROPERTY_TYPE_ANY, 0, 256);
     my $reply = $x->get_property_reply($cookie->{sequence});
diff --git a/testcases/t/001-tile.t b/testcases/t/001-tile.t
index 0db3b83b..066bc640 100644
--- a/testcases/t/001-tile.t
+++ b/testcases/t/001-tile.t
@@ -2,13 +2,7 @@
 # vim:ts=4:sw=4:expandtab
 
 use i3test;
-use X11::XCB qw(:all);
-
-BEGIN {
-    use_ok('X11::XCB::Window');
-}
-
-my $x = X11::XCB::Connection->new;
+use X11::XCB 'WINDOW_CLASS_INPUT_OUTPUT';
 
 my $original_rect = X11::XCB::Rect->new(x => 0, y => 0, width => 30, height => 30);
 
diff --git a/testcases/t/002-i3-sync.t b/testcases/t/002-i3-sync.t
index 7518c949..75871f9d 100644
--- a/testcases/t/002-i3-sync.t
+++ b/testcases/t/002-i3-sync.t
@@ -3,12 +3,8 @@
 #
 # checks if i3 supports I3_SYNC
 #
-use X11::XCB qw(:all);
-use X11::XCB::Connection;
 use i3test;
 
-my $x = X11::XCB::Connection->new;
-
 my $result = sync_with_i3($x);
 ok($result, 'syncing was successful');
 
diff --git a/testcases/t/003-ipc.t b/testcases/t/003-ipc.t
index 982ece7e..296375ab 100644
--- a/testcases/t/003-ipc.t
+++ b/testcases/t/003-ipc.t
@@ -3,8 +3,6 @@
 
 use i3test;
 
-my $x = X11::XCB::Connection->new;
-
 fresh_workspace;
 
 #####################################################################
diff --git a/testcases/t/004-unmanaged.t b/testcases/t/004-unmanaged.t
index 1ef934ee..70bdb557 100644
--- a/testcases/t/004-unmanaged.t
+++ b/testcases/t/004-unmanaged.t
@@ -2,13 +2,7 @@
 # vim:ts=4:sw=4:expandtab
 
 use i3test;
-use X11::XCB qw(:all);
-
-BEGIN {
-    use_ok('X11::XCB::Window');
-}
-
-my $x = X11::XCB::Connection->new;
+use X11::XCB 'WINDOW_CLASS_INPUT_OUTPUT';
 
 my $original_rect = X11::XCB::Rect->new(x => 0, y => 0, width => 30, height => 30);
 
diff --git a/testcases/t/005-floating.t b/testcases/t/005-floating.t
index d605328d..7e6b8922 100644
--- a/testcases/t/005-floating.t
+++ b/testcases/t/005-floating.t
@@ -2,13 +2,7 @@
 # vim:ts=4:sw=4:expandtab
 
 use i3test;
-use X11::XCB qw(:all);
-
-BEGIN {
-    use_ok('X11::XCB::Window');
-}
-
-my $x = X11::XCB::Connection->new;
+use X11::XCB 'WINDOW_CLASS_INPUT_OUTPUT';
 
 # Create a floating window which is smaller than the minimum enforced size of i3
 my $window = $x->root->create_child(
diff --git a/testcases/t/100-fullscreen.t b/testcases/t/100-fullscreen.t
index ae8c63f6..e014da48 100644
--- a/testcases/t/100-fullscreen.t
+++ b/testcases/t/100-fullscreen.t
@@ -2,7 +2,7 @@
 # vim:ts=4:sw=4:expandtab
 
 use i3test;
-use X11::XCB qw(:all);
+use X11::XCB 'WINDOW_CLASS_INPUT_OUTPUT';
 use List::Util qw(first);
 
 my $i3 = i3(get_socket_path());
@@ -26,12 +26,6 @@ for my $o (@outputs) {
     }
 }
 
-BEGIN {
-    use_ok('X11::XCB::Window');
-}
-
-my $x = X11::XCB::Connection->new;
-
 ##################################
 # map a window, then fullscreen it
 ##################################
diff --git a/testcases/t/101-focus.t b/testcases/t/101-focus.t
index 51119007..070d1385 100644
--- a/testcases/t/101-focus.t
+++ b/testcases/t/101-focus.t
@@ -3,8 +3,6 @@
 
 use i3test;
 
-my $x = X11::XCB::Connection->new;
-
 my $tmp = fresh_workspace;
 
 #####################################################################
diff --git a/testcases/t/102-dock.t b/testcases/t/102-dock.t
index 092cf3d2..213052f5 100644
--- a/testcases/t/102-dock.t
+++ b/testcases/t/102-dock.t
@@ -2,15 +2,9 @@
 # vim:ts=4:sw=4:expandtab
 
 use i3test;
-use X11::XCB qw(:all);
+use X11::XCB 'PROP_MODE_REPLACE';
 use List::Util qw(first);
 
-BEGIN {
-    use_ok('X11::XCB::Connection') or BAIL_OUT('Cannot load X11::XCB::Connection');
-}
-
-my $x = X11::XCB::Connection->new;
-
 #####################################################################
 # verify that there is no dock window yet
 #####################################################################
diff --git a/testcases/t/104-focus-stack.t b/testcases/t/104-focus-stack.t
index b5be284c..8807d015 100644
--- a/testcases/t/104-focus-stack.t
+++ b/testcases/t/104-focus-stack.t
@@ -5,8 +5,6 @@
 
 use i3test;
 
-my $x = X11::XCB::Connection->new;
-
 fresh_workspace;
 
 cmd 'split h';
diff --git a/testcases/t/111-goto.t b/testcases/t/111-goto.t
index 76baec0e..0da9e8e0 100644
--- a/testcases/t/111-goto.t
+++ b/testcases/t/111-goto.t
@@ -4,8 +4,6 @@
 use i3test;
 use File::Temp;
 
-my $x = X11::XCB::Connection->new;
-
 my $tmp = fresh_workspace;
 
 cmd 'split h';
diff --git a/testcases/t/112-floating-resize.t b/testcases/t/112-floating-resize.t
index ac3387a9..a428df4f 100644
--- a/testcases/t/112-floating-resize.t
+++ b/testcases/t/112-floating-resize.t
@@ -2,13 +2,6 @@
 # vim:ts=4:sw=4:expandtab
 
 use i3test;
-use X11::XCB qw(:all);
-
-BEGIN {
-    use_ok('X11::XCB::Connection') or BAIL_OUT('Cannot load X11::XCB::Connection');
-}
-
-my $x = X11::XCB::Connection->new;
 
 fresh_workspace;
 
diff --git a/testcases/t/113-urgent.t b/testcases/t/113-urgent.t
index cb547667..2b78b882 100644
--- a/testcases/t/113-urgent.t
+++ b/testcases/t/113-urgent.t
@@ -2,15 +2,8 @@
 # vim:ts=4:sw=4:expandtab
 
 use i3test;
-use X11::XCB qw(:all);
 use List::Util qw(first);
 
-BEGIN {
-    use_ok('X11::XCB::Connection') or BAIL_OUT('Cannot load X11::XCB::Connection');
-}
-
-my $x = X11::XCB::Connection->new;
-
 my $tmp = fresh_workspace;
 
 #####################################################################
diff --git a/testcases/t/114-client-leader.t b/testcases/t/114-client-leader.t
index 6f7ffce0..d2fd16a0 100644
--- a/testcases/t/114-client-leader.t
+++ b/testcases/t/114-client-leader.t
@@ -2,13 +2,6 @@
 # vim:ts=4:sw=4:expandtab
 
 use i3test;
-use X11::XCB qw(:all);
-
-BEGIN {
-    use_ok('X11::XCB::Connection') or BAIL_OUT('Cannot load X11::XCB::Connection');
-}
-
-my $x = X11::XCB::Connection->new;
 
 my $tmp = fresh_workspace;
 
diff --git a/testcases/t/119-match.t b/testcases/t/119-match.t
index 8b9d21d3..80c94ab1 100644
--- a/testcases/t/119-match.t
+++ b/testcases/t/119-match.t
@@ -4,14 +4,13 @@
 # Tests all kinds of matching methods
 #
 use i3test;
-use X11::XCB qw(:all);
+use X11::XCB qw(PROP_MODE_REPLACE WINDOW_CLASS_INPUT_OUTPUT);
 
 my $tmp = fresh_workspace;
 
 ok(@{get_ws_content($tmp)} == 0, 'no containers yet');
 
 # Open a new window
-my $x = X11::XCB::Connection->new;
 my $window = open_window($x);
 my $content = get_ws_content($tmp);
 ok(@{$content} == 1, 'window mapped');
diff --git a/testcases/t/124-move.t b/testcases/t/124-move.t
index a6eb6164..9d7a235f 100644
--- a/testcases/t/124-move.t
+++ b/testcases/t/124-move.t
@@ -8,9 +8,7 @@
 # 4) move a container in a different direction so that we need to go up in tree
 #
 use i3test;
-use X11::XCB::Connection;
 
-my $x = X11::XCB::Connection->new;
 my $i3 = i3(get_socket_path());
 
 my $tmp = fresh_workspace;
diff --git a/testcases/t/129-focus-after-close.t b/testcases/t/129-focus-after-close.t
index 8d225613..1bb2eedc 100644
--- a/testcases/t/129-focus-after-close.t
+++ b/testcases/t/129-focus-after-close.t
@@ -4,11 +4,8 @@
 # Check if the focus is correctly restored after closing windows.
 #
 use i3test;
-use X11::XCB qw(:all);
 use List::Util qw(first);
 
-my $x = X11::XCB::Connection->new;
-
 my $i3 = i3(get_socket_path());
 
 my $tmp = fresh_workspace;
diff --git a/testcases/t/132-move-workspace.t b/testcases/t/132-move-workspace.t
index 82e59dd1..1643fc75 100644
--- a/testcases/t/132-move-workspace.t
+++ b/testcases/t/132-move-workspace.t
@@ -9,7 +9,6 @@ my $i3 = i3(get_socket_path());
 
 # We move the pointer out of our way to avoid a bug where the focus will
 # be set to the window under the cursor
-my $x = X11::XCB::Connection->new;
 $x->root->warp_pointer(0, 0);
 
 my $tmp = get_unused_workspace();
diff --git a/testcases/t/133-size-hints.t b/testcases/t/133-size-hints.t
index d2d77e8e..90ecf62e 100644
--- a/testcases/t/133-size-hints.t
+++ b/testcases/t/133-size-hints.t
@@ -5,8 +5,6 @@
 #
 use i3test;
 
-my $x = X11::XCB::Connection->new;
-
 my $tmp = fresh_workspace;
 
 ok(@{get_ws_content($tmp)} == 0, 'no containers yet');
diff --git a/testcases/t/135-floating-focus.t b/testcases/t/135-floating-focus.t
index 5e5a68f2..bae983e7 100644
--- a/testcases/t/135-floating-focus.t
+++ b/testcases/t/135-floating-focus.t
@@ -2,10 +2,6 @@
 # vim:ts=4:sw=4:expandtab
 
 use i3test;
-use X11::XCB qw(:all);
-use X11::XCB::Connection;
-
-my $x = X11::XCB::Connection->new;
 
 my $tmp = fresh_workspace;
 
diff --git a/testcases/t/136-floating-ws-empty.t b/testcases/t/136-floating-ws-empty.t
index a6e0e405..1666884e 100644
--- a/testcases/t/136-floating-ws-empty.t
+++ b/testcases/t/136-floating-ws-empty.t
@@ -3,11 +3,6 @@
 # Regression test: when only having a floating window on a workspace, it should not be deleted.
 
 use i3test;
-use X11::XCB qw(:all);
-
-BEGIN {
-    use_ok('X11::XCB::Window');
-}
 
 my $i3 = i3(get_socket_path());
 
@@ -19,8 +14,6 @@ my $tmp = fresh_workspace;
 
 ok(workspace_exists($tmp), "workspace $tmp exists");
 
-my $x = X11::XCB::Connection->new;
-
 # Create a floating window which is smaller than the minimum enforced size of i3
 my $window = open_floating_window($x);
 ok($window->mapped, 'Window is mapped');
diff --git a/testcases/t/137-floating-unmap.t b/testcases/t/137-floating-unmap.t
index ab1a33d3..29762594 100644
--- a/testcases/t/137-floating-unmap.t
+++ b/testcases/t/137-floating-unmap.t
@@ -4,11 +4,6 @@
 # to a different workspace.
 
 use i3test;
-use X11::XCB qw(:all);
-
-BEGIN {
-    use_ok('X11::XCB::Window');
-}
 
 my $i3 = i3(get_socket_path());
 
@@ -18,8 +13,6 @@ my $tmp = fresh_workspace;
 # 1: open a floating window, get it mapped
 #############################################################################
 
-my $x = X11::XCB::Connection->new;
-
 # Create a floating window which is smaller than the minimum enforced size of i3
 my $window = open_floating_window($x);
 ok($window->mapped, 'Window is mapped');
diff --git a/testcases/t/138-floating-attach.t b/testcases/t/138-floating-attach.t
index ae035f61..9a7996b1 100644
--- a/testcases/t/138-floating-attach.t
+++ b/testcases/t/138-floating-attach.t
@@ -4,11 +4,6 @@
 # if only a floating window is present on the workspace.
 
 use i3test;
-use X11::XCB qw(:all);
-
-BEGIN {
-    use_ok('X11::XCB::Window');
-}
 
 my $i3 = i3(get_socket_path());
 
@@ -18,8 +13,6 @@ my $tmp = fresh_workspace;
 # 1: open a floating window, get it mapped
 #############################################################################
 
-my $x = X11::XCB::Connection->new;
-
 # Create a floating window
 my $window = open_floating_window($x);
 ok($window->mapped, 'Window is mapped');
diff --git a/testcases/t/139-ws-numbers.t b/testcases/t/139-ws-numbers.t
index 31f013ef..9d73ad1c 100644
--- a/testcases/t/139-ws-numbers.t
+++ b/testcases/t/139-ws-numbers.t
@@ -3,14 +3,8 @@
 # Check if numbered workspaces and named workspaces are sorted in the right way
 # in get_workspaces IPC output (necessary for i3bar etc.).
 use i3test;
-use X11::XCB qw(:all);
-
-BEGIN {
-    use_ok('X11::XCB::Window');
-}
 
 my $i3 = i3(get_socket_path());
-my $x = X11::XCB::Connection->new;
 
 sub check_order {
     my ($msg) = @_;
diff --git a/testcases/t/140-focus-lost.t b/testcases/t/140-focus-lost.t
index fb77f01e..cd6eee38 100644
--- a/testcases/t/140-focus-lost.t
+++ b/testcases/t/140-focus-lost.t
@@ -3,14 +3,8 @@
 # Regression: Check if the focus stays the same when switching the layout
 # bug introduced by 77d0d42ed2d7ac8cafe267c92b35a81c1b9491eb
 use i3test;
-use X11::XCB qw(:all);
-
-BEGIN {
-    use_ok('X11::XCB::Window');
-}
 
 my $i3 = i3(get_socket_path());
-my $x = X11::XCB::Connection->new;
 
 sub check_order {
     my ($msg) = @_;
diff --git a/testcases/t/141-resize.t b/testcases/t/141-resize.t
index 8691a044..18e28ccb 100644
--- a/testcases/t/141-resize.t
+++ b/testcases/t/141-resize.t
@@ -2,13 +2,6 @@
 # vim:ts=4:sw=4:expandtab
 # Tests resizing tiling containers
 use i3test;
-use X11::XCB qw(:all);
-
-BEGIN {
-    use_ok('X11::XCB::Window');
-}
-
-my $x = X11::XCB::Connection->new;
 
 my $tmp = fresh_workspace;
 
diff --git a/testcases/t/144-regress-floating-resize.t b/testcases/t/144-regress-floating-resize.t
index 44a67bc3..fa1edda5 100644
--- a/testcases/t/144-regress-floating-resize.t
+++ b/testcases/t/144-regress-floating-resize.t
@@ -8,9 +8,6 @@
 #
 use i3test;
 use List::Util qw(sum);
-use X11::XCB::Connection;
-
-my $x = X11::XCB::Connection->new;
 
 my $tmp = fresh_workspace;
 
diff --git a/testcases/t/145-flattening.t b/testcases/t/145-flattening.t
index 6810f479..8baf9217 100644
--- a/testcases/t/145-flattening.t
+++ b/testcases/t/145-flattening.t
@@ -10,11 +10,8 @@
 #
 # This testcase checks that the tree is properly flattened after moving.
 #
-use X11::XCB qw(:all);
 use i3test;
 
-my $x = X11::XCB::Connection->new;
-
 my $tmp = fresh_workspace;
 
 my $left = open_window($x);
diff --git a/testcases/t/146-floating-reinsert.t b/testcases/t/146-floating-reinsert.t
index b63e7ac9..1015f8f8 100644
--- a/testcases/t/146-floating-reinsert.t
+++ b/testcases/t/146-floating-reinsert.t
@@ -1,15 +1,8 @@
 #!perl
 # vim:ts=4:sw=4:expandtab
 #
-use X11::XCB qw(:all);
 use i3test;
 
-BEGIN {
-    use_ok('X11::XCB::Window');
-}
-
-my $x = X11::XCB::Connection->new;
-
 my $tmp = fresh_workspace;
 
 my $left = open_window($x);
diff --git a/testcases/t/147-regress-floatingmove.t b/testcases/t/147-regress-floatingmove.t
index 5f14741b..74adef69 100644
--- a/testcases/t/147-regress-floatingmove.t
+++ b/testcases/t/147-regress-floatingmove.t
@@ -4,16 +4,8 @@
 # Regression test for moving a con outside of a floating con when there are no
 # tiling cons on a workspace
 #
-use X11::XCB qw(:all);
-use Time::HiRes qw(sleep);
 use i3test;
 
-BEGIN {
-    use_ok('X11::XCB::Window');
-}
-
-my $x = X11::XCB::Connection->new;
-
 my $tmp = fresh_workspace;
 
 my $left = open_window($x);
diff --git a/testcases/t/148-regress-floatingmovews.t b/testcases/t/148-regress-floatingmovews.t
index 6f9dfc40..0e6345b2 100644
--- a/testcases/t/148-regress-floatingmovews.t
+++ b/testcases/t/148-regress-floatingmovews.t
@@ -4,15 +4,8 @@
 # Regression test for correct focus behaviour when moving a floating con to
 # another workspace.
 #
-use X11::XCB qw(:all);
 use i3test;
 
-BEGIN {
-    use_ok('X11::XCB::Window');
-}
-
-my $x = X11::XCB::Connection->new;
-
 my $tmp = fresh_workspace;
 
 # open a tiling window on the first workspace
diff --git a/testcases/t/150-regress-dock-restart.t b/testcases/t/150-regress-dock-restart.t
index e294e6bd..a28e0730 100644
--- a/testcases/t/150-regress-dock-restart.t
+++ b/testcases/t/150-regress-dock-restart.t
@@ -3,15 +3,8 @@
 #
 # Regression test for inplace restarting with dock clients
 #
-use X11::XCB qw(:all);
 use i3test;
 
-BEGIN {
-    use_ok('X11::XCB::Window');
-}
-
-my $x = X11::XCB::Connection->new;
-
 my $tmp = fresh_workspace;
 
 #####################################################################
diff --git a/testcases/t/153-floating-originalsize.t b/testcases/t/153-floating-originalsize.t
index db0b6e9c..2c798cfa 100644
--- a/testcases/t/153-floating-originalsize.t
+++ b/testcases/t/153-floating-originalsize.t
@@ -3,13 +3,10 @@
 #
 # Test if the requested width/height is set after making the window floating.
 #
-use X11::XCB qw(:all);
 use i3test;
 
 my $tmp = fresh_workspace;
 
-my $x = X11::XCB::Connection->new;
-
 # Create a floating window which is smaller than the minimum enforced size of i3
 my $window = open_window($x, { rect => [ 0, 0, 400, 150 ] });
 
diff --git a/testcases/t/154-regress-multiple-dock.t b/testcases/t/154-regress-multiple-dock.t
index 8b7f456c..52ab4004 100644
--- a/testcases/t/154-regress-multiple-dock.t
+++ b/testcases/t/154-regress-multiple-dock.t
@@ -3,15 +3,8 @@
 #
 # Regression test for closing one of multiple dock clients
 #
-use X11::XCB qw(:all);
 use i3test;
 
-BEGIN {
-    use_ok('X11::XCB::Window');
-}
-
-my $x = X11::XCB::Connection->new;
-
 my $tmp = fresh_workspace;
 
 #####################################################################
diff --git a/testcases/t/155-floating-split-size.t b/testcases/t/155-floating-split-size.t
index 5de05e8b..618266b6 100644
--- a/testcases/t/155-floating-split-size.t
+++ b/testcases/t/155-floating-split-size.t
@@ -4,15 +4,8 @@
 # Test to see if i3 combines the geometry of all children in a split container
 # when setting the split container to floating
 #
-use X11::XCB qw(:all);
 use i3test;
 
-BEGIN {
-    use_ok('X11::XCB::Window');
-}
-
-my $x = X11::XCB::Connection->new;
-
 my $tmp = fresh_workspace;
 
 #####################################################################
diff --git a/testcases/t/156-fullscreen-focus.t b/testcases/t/156-fullscreen-focus.t
index a559b5a5..e188b375 100644
--- a/testcases/t/156-fullscreen-focus.t
+++ b/testcases/t/156-fullscreen-focus.t
@@ -4,14 +4,8 @@
 # Test if new containers get focused when there is a fullscreen container at
 # the time of launching the new one.
 #
-use X11::XCB qw(:all);
 use i3test;
 
-BEGIN {
-    use_ok('X11::XCB::Window');
-}
-
-my $x = X11::XCB::Connection->new;
 my $i3 = i3(get_socket_path());
 
 my $tmp = fresh_workspace;
diff --git a/testcases/t/157-regress-fullscreen-level-up.t b/testcases/t/157-regress-fullscreen-level-up.t
index f067cb93..2c9c4b17 100644
--- a/testcases/t/157-regress-fullscreen-level-up.t
+++ b/testcases/t/157-regress-fullscreen-level-up.t
@@ -3,15 +3,8 @@
 #
 # Regression test: level up should be a noop during fullscreen mode
 #
-use X11::XCB qw(:all);
 use i3test;
 
-BEGIN {
-    use_ok('X11::XCB::Window');
-}
-
-my $x = X11::XCB::Connection->new;
-
 my $tmp = fresh_workspace;
 
 #####################################################################
diff --git a/testcases/t/158-wm_take_focus.t b/testcases/t/158-wm_take_focus.t
index a90ce1c3..3da8d907 100644
--- a/testcases/t/158-wm_take_focus.t
+++ b/testcases/t/158-wm_take_focus.t
@@ -3,11 +3,7 @@
 #
 # Tests if the WM_TAKE_FOCUS protocol is correctly handled by i3
 #
-use X11::XCB qw(:all);
 use i3test;
-use v5.10;
-
-my $x = X11::XCB::Connection->new;
 
 subtest 'Window without WM_TAKE_FOCUS', sub {
     fresh_workspace;
diff --git a/testcases/t/161-regress-borders-restart.t b/testcases/t/161-regress-borders-restart.t
index c5e3ef80..ce53b002 100644
--- a/testcases/t/161-regress-borders-restart.t
+++ b/testcases/t/161-regress-borders-restart.t
@@ -5,11 +5,9 @@
 # restart.
 # found in eb8ad348b28e243cba1972e802ca8ee636472fc9
 #
-use X11::XCB qw(:all);
 use List::Util qw(first);
 use i3test;
 
-my $x = X11::XCB::Connection->new;
 my $i3 = i3(get_socket_path());
 my $tmp = fresh_workspace;
 my $window = open_window($x);
diff --git a/testcases/t/162-regress-dock-urgent.t b/testcases/t/162-regress-dock-urgent.t
index 5fb88129..39e4eac4 100644
--- a/testcases/t/162-regress-dock-urgent.t
+++ b/testcases/t/162-regress-dock-urgent.t
@@ -4,14 +4,9 @@
 # Regression test for setting the urgent hint on dock clients.
 # found in 4be3178d4d360c2996217d811e61161c84d25898
 #
-use X11::XCB qw(:all);
 use i3test;
+use X11::XCB 'WINDOW_CLASS_INPUT_OUTPUT';
 
-BEGIN {
-    use_ok('X11::XCB::Window');
-}
-
-my $x = X11::XCB::Connection->new;
 my $i3 = i3(get_socket_path());
 
 my $tmp = fresh_workspace;
diff --git a/testcases/t/163-wm-state.t b/testcases/t/163-wm-state.t
index e55d8682..e5b42df4 100644
--- a/testcases/t/163-wm-state.t
+++ b/testcases/t/163-wm-state.t
@@ -4,10 +4,8 @@
 # Tests if WM_STATE is WM_STATE_NORMAL when mapped and WM_STATE_WITHDRAWN when
 # unmapped.
 #
-use X11::XCB qw(:all);
 use i3test;
-
-my $x = X11::XCB::Connection->new;
+use X11::XCB qw(ICCCM_WM_STATE_NORMAL ICCCM_WM_STATE_WITHDRAWN);
 
 my $window = open_window($x);
 
diff --git a/testcases/t/164-kill-win-vs-client.t b/testcases/t/164-kill-win-vs-client.t
index 41ae6432..df9b7fd8 100644
--- a/testcases/t/164-kill-win-vs-client.t
+++ b/testcases/t/164-kill-win-vs-client.t
@@ -6,8 +6,6 @@
 #
 use i3test;
 
-my $x = X11::XCB::Connection->new;
-
 sub two_windows {
     my $tmp = fresh_workspace;
 
diff --git a/testcases/t/165-for_window.t b/testcases/t/165-for_window.t
index b3fef117..88c542eb 100644
--- a/testcases/t/165-for_window.t
+++ b/testcases/t/165-for_window.t
@@ -3,11 +3,8 @@
 # !NO_I3_INSTANCE! will prevent complete-run.pl from starting i3
 #
 #
-use X11::XCB qw(:all);
-use X11::XCB::Connection;
 use i3test;
-
-my $x = X11::XCB::Connection->new;
+use X11::XCB qw(PROP_MODE_REPLACE WINDOW_CLASS_INPUT_OUTPUT);
 
 ##############################################################
 # 1: test the following directive:
diff --git a/testcases/t/166-assign.t b/testcases/t/166-assign.t
index 9492486c..d2bb9fa7 100644
--- a/testcases/t/166-assign.t
+++ b/testcases/t/166-assign.t
@@ -5,11 +5,7 @@
 # Tests if assignments work
 #
 use i3test;
-use X11::XCB qw(:all);
-use X11::XCB::Connection;
-use v5.10;
-
-my $x = X11::XCB::Connection->new;
+use X11::XCB qw(PROP_MODE_REPLACE WINDOW_CLASS_INPUT_OUTPUT);
 
 # TODO: move to X11::XCB
 sub set_wm_class {
diff --git a/testcases/t/167-workspace_layout.t b/testcases/t/167-workspace_layout.t
index 553717c5..2744c9ba 100644
--- a/testcases/t/167-workspace_layout.t
+++ b/testcases/t/167-workspace_layout.t
@@ -6,10 +6,6 @@
 #
 
 use i3test;
-use X11::XCB qw(:all);
-use X11::XCB::Connection;
-
-my $x = X11::XCB::Connection->new;
 
 #####################################################################
 # 1: check that with an empty config, cons are place next to each
diff --git a/testcases/t/168-regress-fullscreen-restart.t b/testcases/t/168-regress-fullscreen-restart.t
index 1418b402..70bddd8e 100644
--- a/testcases/t/168-regress-fullscreen-restart.t
+++ b/testcases/t/168-regress-fullscreen-restart.t
@@ -4,10 +4,6 @@
 # Verifies that i3 survives inplace restarts with fullscreen containers
 #
 use i3test;
-use X11::XCB qw(:all);
-use X11::XCB::Connection;
-
-my $x = X11::XCB::Connection->new;
 
 fresh_workspace;
 
diff --git a/testcases/t/170-force_focus_wrapping.t b/testcases/t/170-force_focus_wrapping.t
index d2f15a65..b8920c2d 100644
--- a/testcases/t/170-force_focus_wrapping.t
+++ b/testcases/t/170-force_focus_wrapping.t
@@ -6,8 +6,6 @@
 #
 use i3test;
 
-my $x = i3test::X11->new;
-
 #####################################################################
 # 1: test the wrapping behaviour without force_focus_wrapping
 #####################################################################
diff --git a/testcases/t/172-start-on-named-ws.t b/testcases/t/172-start-on-named-ws.t
index cdd2001d..97ae16e9 100644
--- a/testcases/t/172-start-on-named-ws.t
+++ b/testcases/t/172-start-on-named-ws.t
@@ -4,12 +4,8 @@
 #
 # checks if i3 starts up on workspace '1' or the first configured named workspace
 #
-use X11::XCB qw(:all);
-use X11::XCB::Connection;
 use i3test;
 
-my $x = X11::XCB::Connection->new;
-
 ##############################################################
 # 1: i3 should start with workspace '1'
 ##############################################################
diff --git a/testcases/t/173-regress-focus-assign.t b/testcases/t/173-regress-focus-assign.t
index 70414af3..bd0ff647 100644
--- a/testcases/t/173-regress-focus-assign.t
+++ b/testcases/t/173-regress-focus-assign.t
@@ -6,11 +6,7 @@
 # assigned to an invisible workspace
 #
 use i3test;
-use X11::XCB qw(:all);
-use X11::XCB::Connection;
-use v5.10;
-
-my $x = X11::XCB::Connection->new;
+use X11::XCB qw(PROP_MODE_REPLACE WINDOW_CLASS_INPUT_OUTPUT);
 
 # TODO: move to X11::XCB
 sub set_wm_class {
diff --git a/testcases/t/174-border-config.t b/testcases/t/174-border-config.t
index cc1f5c90..a27126cb 100644
--- a/testcases/t/174-border-config.t
+++ b/testcases/t/174-border-config.t
@@ -7,8 +7,6 @@
 
 use i3test;
 
-my $x = X11::XCB::Connection->new;
-
 #####################################################################
 # 1: check that new windows start with 'normal' border unless configured
 # otherwise
diff --git a/testcases/t/175-startup-notification.t b/testcases/t/175-startup-notification.t
index 55df4142..b624508b 100644
--- a/testcases/t/175-startup-notification.t
+++ b/testcases/t/175-startup-notification.t
@@ -8,7 +8,6 @@ use i3test;
 use POSIX qw(mkfifo);
 use File::Temp qw(:POSIX);
 
-my $x = X11::XCB::Connection->new;
 use ExtUtils::PkgConfig;
 
 # setup dependency on libstartup-notification using pkg-config
diff --git a/testcases/t/176-workspace-baf.t b/testcases/t/176-workspace-baf.t
index 48ea948d..31c4f248 100644
--- a/testcases/t/176-workspace-baf.t
+++ b/testcases/t/176-workspace-baf.t
@@ -7,9 +7,6 @@
 #
 
 use i3test;
-use X11::XCB::Connection;
-
-my $x = X11::XCB::Connection->new;
 
 my $config = <<EOT;
 # i3 config file (v4)