diff --git a/frontend/xwayland.c b/frontend/xwayland.c
index 8845e85a4..172f12e9b 100644
--- a/frontend/xwayland.c
+++ b/frontend/xwayland.c
@@ -112,6 +112,8 @@ spawn_xserver(void *user_data, const char *display, int abstract_fd, int unix_fd
 	struct fdstr x11_wm_socket = FDSTR_INIT;
 	struct fdstr display_pipe = FDSTR_INIT;
 	char *xserver = NULL;
+	char *extra_args = NULL;
+	struct weston_string_array extra_args_array = { 0 };
 	struct weston_config *config = wet_get_config(wxw->compositor);
 	struct weston_config_section *section;
 	struct wl_client *client;
@@ -154,6 +156,10 @@ spawn_xserver(void *user_data, const char *display, int abstract_fd, int unix_fd
 	section = weston_config_get_section(config, "xwayland", NULL, NULL);
 	weston_config_section_get_string(section, "path",
 					 &xserver, XSERVER_PATH);
+	weston_config_section_get_string(section, "extra-args", &extra_args, NULL);
+	if (extra_args)
+		extra_args_array = weston_parse_space_separated_list(extra_args);
+
 	custom_env_init_from_environ(&child_env);
 	custom_env_set_env_var(&child_env, "WAYLAND_SOCKET", wayland_socket.str1);
 
@@ -170,6 +176,9 @@ spawn_xserver(void *user_data, const char *display, int abstract_fd, int unix_fd
 	custom_env_add_arg(&child_env, x11_wm_socket.str1);
 	custom_env_add_arg(&child_env, "-terminate");
 
+	for (size_t i = 0; i < extra_args_array.len; i++)
+		custom_env_add_arg(&child_env, extra_args_array.array[i]);
+
 	wxw->process =
 		wet_client_launch(wxw->compositor, &child_env,
 				  no_cloexec_fds, num_no_cloexec_fds,
@@ -208,6 +217,10 @@ spawn_xserver(void *user_data, const char *display, int abstract_fd, int unix_fd
 				     handle_display_fd, wxw);
 
 	free(xserver);
+	if (extra_args)
+		free(extra_args);
+	if (extra_args_array.array)
+		weston_string_array_fini(&extra_args_array);
 
 	return client;
 
@@ -216,6 +229,10 @@ err_proc:
 	wl_list_remove(&wxw->process->link);
 err:
 	free(xserver);
+	if (extra_args)
+		free(extra_args);
+	if (extra_args_array.array)
+		weston_string_array_fini(&extra_args_array);
 	fdstr_close_all(&display_pipe);
 	fdstr_close_all(&x11_wm_socket);
 	fdstr_close_all(&wayland_socket);
diff --git a/tests/harness/weston-test-fixture-compositor.c b/tests/harness/weston-test-fixture-compositor.c
index 6ec245721..07b142ff5 100644
--- a/tests/harness/weston-test-fixture-compositor.c
+++ b/tests/harness/weston-test-fixture-compositor.c
@@ -193,6 +193,7 @@ compositor_setup_defaults_(struct compositor_setup *setup,
 		.renderer = WESTON_RENDERER_NOOP,
 		.shell = SHELL_TEST_DESKTOP,
 		.xwayland = false,
+		.xwayland_extra_args = NULL,
 		.width = 320,
 		.height = 240,
 		.scale = 1,
@@ -490,6 +491,14 @@ weston_ini_setup_(struct compositor_setup *setup, ...)
 	weston_ini = open_ini_file(setup);
 	test_assert_ptr_not_null(weston_ini);
 
+	/* Write xwayland section if extra args are specified */
+	if (setup->xwayland_extra_args) {
+		ret = fprintf(weston_ini, "[xwayland]\n");
+		test_assert_int_ge(ret, 0);
+		ret = fprintf(weston_ini, "extra-args=%s\n", setup->xwayland_extra_args);
+		test_assert_int_ge(ret, 0);
+	}
+
 	va_start(entry_list, setup);
 	write_cfg(entry_list, weston_ini);
 	va_end(entry_list);
diff --git a/tests/harness/weston-test-fixture-compositor.h b/tests/harness/weston-test-fixture-compositor.h
index 0050d8672..6cc24d352 100644
--- a/tests/harness/weston-test-fixture-compositor.h
+++ b/tests/harness/weston-test-fixture-compositor.h
@@ -75,6 +75,8 @@ struct compositor_setup {
 	enum shell_type shell;
 	/** Whether to enable xwayland support. */
 	bool xwayland;
+	/** Extra arguments to pass to Xwayland, or NULL for none. */
+	const char *xwayland_extra_args;
 	/** Default output width. */
 	unsigned width;
 	/** Default output height. */
@@ -113,6 +115,7 @@ compositor_setup_defaults_(struct compositor_setup *setup,
  * - renderer: noop
  * - shell: test desktop shell
  * - xwayland: no
+ * - xwayland_extra_args: none
  * - width: 320
  * - height: 240
  * - refresh: 0 (repaint only on demand)
diff --git a/tests/xwayland-test.c b/tests/xwayland-test.c
index 948ea4269..ee8284bde 100644
--- a/tests/xwayland-test.c
+++ b/tests/xwayland-test.c
@@ -48,8 +48,24 @@
 #include "weston-test-assert.h"
 #include "xcb-client-helper.h"
 
+struct setup_args {
+	struct fixture_metadata meta;
+	const char *extra_args;
+};
+
+static const struct setup_args my_setup_args[] = {
+	{
+		.extra_args = "-extension MIT-SHM",
+		.meta.name = "MIT-SHM-disabled"
+	},
+	{
+		.extra_args = "+extension MIT-SHM",
+		.meta.name = "MIT-SHM-enabled"
+	},
+};
+
 static enum test_result_code
-fixture_setup(struct weston_test_harness *harness)
+fixture_setup(struct weston_test_harness *harness, const struct setup_args *arg)
 {
 	struct compositor_setup setup;
 
@@ -59,11 +75,14 @@ fixture_setup(struct weston_test_harness *harness)
 	setup.shell = SHELL_TEST_DESKTOP;
 	setup.refresh = HIGHEST_OUTPUT_REFRESH;
 	setup.xwayland = true;
+	setup.xwayland_extra_args = arg->extra_args;
 	setup.logging_scopes = "log,xwm-wm-x11";
 
+	weston_ini_setup(&setup, NULL);
+
 	return weston_test_harness_execute_as_client(harness, &setup);
 }
-DECLARE_FIXTURE_SETUP(fixture_setup);
+DECLARE_FIXTURE_SETUP_WITH_ARG(fixture_setup, my_setup_args, meta);
 
 static char *
 get_x11_window_name(struct window_x11 *window, xcb_drawable_t win)