diff --git a/meson.build b/meson.build
index 5c1587c3..81ed954c 100644
--- a/meson.build
+++ b/meson.build
@@ -156,8 +156,9 @@ if not cc.has_header_symbol('sys/ptrace.h', 'PTRACE_ATTACH', prefix : prefix)
 	config_h.set('PTRACE_CONT', 'PT_CONTINUE')
 	config_h.set('PTRACE_DETACH', 'PT_DETACH')
 endif
-
-config_h.set10('HAVE_INSTALLED_TESTS', get_option('install-tests'))
+if get_option('install-tests')
+	config_h.set('HAVE_INSTALLED_TESTS', 1)
+endif
 
 # Dependencies
 pkgconfig = import('pkgconfig')
@@ -174,8 +175,8 @@ includes_src = include_directories('src')
 ############ mtdev configuration ############
 
 have_mtdev = get_option('mtdev')
-config_h.set10('HAVE_MTDEV', have_mtdev)
 if have_mtdev
+	config_h.set('HAVE_MTDEV', 1)
 	dep_mtdev = dependency('mtdev', version : '>= 1.1.0')
 else
 	dep_mtdev = declare_dependency()
@@ -184,8 +185,8 @@ endif
 ############ libwacom configuration ############
 
 have_libwacom = get_option('libwacom')
-config_h.set10('HAVE_LIBWACOM', have_libwacom)
 if have_libwacom
+	config_h.set('HAVE_LIBWACOM', 1)
 	dep_libwacom = dependency('libwacom', version : '>= 0.27')
 	if cc.has_header_symbol('libwacom/libwacom.h', 'WACOM_BUTTON_DIAL_MODESWITCH',
 				dependencies : dep_libwacom)
@@ -612,13 +613,16 @@ executable('libinput-record',
 	   install : true,
 	   )
 
-config_h.set10('HAVE_DEBUG_GUI', get_option('debug-gui'))
 if get_option('debug-gui')
+	config_h.set('HAVE_DEBUG_GUI', 1)
 	dep_gtk = dependency('gtk4', version : '>= 4.0', required : false)
-	config_h.set10('HAVE_GTK4', dep_gtk.found())
-	if not dep_gtk.found()
+	if dep_gtk.found()
+		config_h.set('HAVE_GTK4', 1)
+	else
 		dep_gtk = dependency('gtk+-3.0', version : '>= 3.20')
-		config_h.set10('HAVE_GTK3', dep_gtk.found())
+		if dep_gtk.found()
+			config_h.set('HAVE_GTK3', 1)
+		endif
 	endif
 
 	if meson.version().version_compare('>= 0.58')
@@ -636,8 +640,9 @@ if get_option('debug-gui')
 	dep_wayland_client = dependency('wayland-client', required : false)
 	dep_wayland_protocols = dependency('wayland-protocols', required : false)
 
-	config_h.set10('HAVE_GTK_X11', have_gtk_x11 and dep_x11.found())
-	config_h.set10('HAVE_GTK_WAYLAND', false)
+	if have_gtk_x11 and dep_x11.found()
+		config_h.set('HAVE_GTK_X11', 1)
+	endif
 
 	debug_gui_sources = [ 'tools/libinput-debug-gui.c' ]
 
@@ -665,7 +670,7 @@ if get_option('debug-gui')
 		)
 
 		debug_gui_sources += [ wayland_headers, wayland_sources ]
-		config_h.set10('HAVE_GTK_WAYLAND', true)
+		config_h.set('HAVE_GTK_WAYLAND', 1)
 	endif
 
 	deps_debug_gui = [
@@ -791,11 +796,15 @@ if get_option('tests')
 	dep_check = dependency('check', version : '>= 0.9.10', required: false)
 
 	gstack = find_program('gstack', required : false)
-	config_h.set10('HAVE_GSTACK', gstack.found())
+	if gstack.found()
+		config_h.set('HAVE_GSTACK', 1)
+	endif
 
 	# for inhibit support during test run
 	dep_libsystemd = dependency('libsystemd', version : '>= 221', required : false)
-	config_h.set10('HAVE_LIBSYSTEMD', dep_libsystemd.found())
+	if dep_libsystemd.found()
+		config_h.set('HAVE_LIBSYSTEMD', 1)
+	endif
 
 	litest_sources = [
 		'src/libinput-private-config.c',
diff --git a/src/evdev-mt-touchpad.c b/src/evdev-mt-touchpad.c
index f819a2ad..d161ab6a 100644
--- a/src/evdev-mt-touchpad.c
+++ b/src/evdev-mt-touchpad.c
@@ -28,7 +28,7 @@
 #include <math.h>
 #include <stdbool.h>
 
-#if HAVE_LIBWACOM
+#ifdef HAVE_LIBWACOM
 #include <libwacom/libwacom.h>
 #endif
 
@@ -3742,7 +3742,7 @@ static bool
 tp_requires_rotation(struct tp_dispatch *tp, struct evdev_device *device)
 {
 	bool rotate = false;
-#if HAVE_LIBWACOM
+#ifdef HAVE_LIBWACOM
 	struct libinput *li = tp_libinput_context(tp);
 	WacomDeviceDatabase *db = NULL;
 	WacomDevice **devices = NULL, **d;
diff --git a/src/evdev-tablet-pad-leds.c b/src/evdev-tablet-pad-leds.c
index aa411202..7aca1e1d 100644
--- a/src/evdev-tablet-pad-leds.c
+++ b/src/evdev-tablet-pad-leds.c
@@ -28,7 +28,7 @@
 
 #include "evdev-tablet-pad.h"
 
-#if HAVE_LIBWACOM
+#ifdef HAVE_LIBWACOM
 #include <libwacom/libwacom.h>
 #endif
 
@@ -114,7 +114,7 @@ pad_led_destroy(struct libinput *libinput, struct pad_mode_led *led)
 	free(led);
 }
 
-#if HAVE_LIBWACOM
+#ifdef HAVE_LIBWACOM
 static inline struct pad_mode_led *
 pad_led_new(struct libinput *libinput, const char *prefix, int group, int mode)
 {
@@ -198,7 +198,7 @@ pad_get_mode_group(struct pad_dispatch *pad, unsigned int index)
 	return NULL;
 }
 
-#if HAVE_LIBWACOM
+#ifdef HAVE_LIBWACOM
 static inline bool
 is_litest_device(struct evdev_device *device)
 {
@@ -618,7 +618,7 @@ pad_init_leds(struct pad_dispatch *pad, struct evdev_device *device, WacomDevice
 	}
 
 	/* If libwacom fails, we init one fallback group anyway */
-#if HAVE_LIBWACOM
+#ifdef HAVE_LIBWACOM
 	rc = pad_init_leds_from_libwacom(pad, device, wacom);
 #endif
 	if (rc != 0)
diff --git a/src/evdev-tablet-pad.c b/src/evdev-tablet-pad.c
index c1e387c5..5bd58db0 100644
--- a/src/evdev-tablet-pad.c
+++ b/src/evdev-tablet-pad.c
@@ -31,7 +31,7 @@
 
 #include "evdev-tablet-pad.h"
 
-#if HAVE_LIBWACOM
+#ifdef HAVE_LIBWACOM
 #include <libwacom/libwacom.h>
 #endif
 
@@ -667,7 +667,7 @@ pad_init_buttons_from_libwacom(struct pad_dispatch *pad,
 			       WacomDevice *tablet)
 {
 	bool rc = false;
-#if HAVE_LIBWACOM
+#ifdef HAVE_LIBWACOM
 
 	if (tablet) {
 		int num_buttons = libwacom_get_num_buttons(tablet);
@@ -759,7 +759,7 @@ pad_init_left_handed(struct evdev_device *device, WacomDevice *wacom)
 {
 	bool has_left_handed = true;
 
-#if HAVE_LIBWACOM
+#ifdef HAVE_LIBWACOM
 	has_left_handed = !wacom || libwacom_is_reversible(wacom);
 #endif
 	if (has_left_handed)
@@ -772,7 +772,7 @@ pad_init(struct pad_dispatch *pad, struct evdev_device *device)
 	int rc = 1;
 	struct libinput *li = evdev_libinput_context(device);
 	WacomDevice *wacom = NULL;
-#if HAVE_LIBWACOM
+#ifdef HAVE_LIBWACOM
 	WacomDeviceDatabase *db = libinput_libwacom_ref(li);
 	if (db) {
 		char event_path[64];
@@ -825,7 +825,7 @@ pad_init(struct pad_dispatch *pad, struct evdev_device *device)
 	/* at most 5 "Multiple EV_ABS events" log messages per hour */
 	ratelimit_init(&pad->duplicate_abs_limit, s2us(60 * 60), 5);
 
-#if HAVE_LIBWACOM
+#ifdef HAVE_LIBWACOM
 	if (wacom)
 		libwacom_destroy(wacom);
 	if (db)
diff --git a/src/evdev-tablet-pad.h b/src/evdev-tablet-pad.h
index 8e07d519..76014c8d 100644
--- a/src/evdev-tablet-pad.h
+++ b/src/evdev-tablet-pad.h
@@ -26,7 +26,7 @@
 
 #include "evdev.h"
 
-#if !HAVE_LIBWACOM
+#ifndef HAVE_LIBWACOM
 typedef void *WacomDevice;
 #endif
 
diff --git a/src/evdev-tablet.c b/src/evdev-tablet.c
index 77fae45f..f77ba967 100644
--- a/src/evdev-tablet.c
+++ b/src/evdev-tablet.c
@@ -31,7 +31,7 @@
 
 #include "evdev-tablet.h"
 
-#if HAVE_LIBWACOM
+#ifdef HAVE_LIBWACOM
 #include <libwacom/libwacom.h>
 #else
 typedef void *WacomStylus;
@@ -1004,7 +1004,7 @@ tool_set_bits_from_libwacom(const struct tablet_dispatch *tablet,
 			    const WacomStylus *s)
 {
 	bool rc = false;
-#if HAVE_LIBWACOM
+#ifdef HAVE_LIBWACOM
 	int code;
 	WacomStylusType type;
 	WacomAxisTypeFlags axes;
@@ -1369,7 +1369,7 @@ tool_init_eraser_button(struct tablet_dispatch *tablet,
 	if (libinput_tablet_tool_get_type(tool) != LIBINPUT_TABLET_TOOL_TYPE_PEN)
 		return;
 
-#if HAVE_LIBWACOM
+#ifdef HAVE_LIBWACOM
 	/* libwacom's API is a bit terrible here:
 	 * - has_eraser is true on styli that have a separate eraser, all
 	 *   those are INVERT so we can exclude them
@@ -1400,7 +1400,7 @@ tablet_new_tool(struct tablet_dispatch *tablet,
 {
 	struct libinput_tablet_tool *tool = zalloc(sizeof *tool);
 	const WacomStylus *s = NULL;
-#if HAVE_LIBWACOM
+#ifdef HAVE_LIBWACOM
 	WacomDeviceDatabase *db;
 
 	db = tablet_libinput_context(tablet)->libwacom.db;
@@ -2788,7 +2788,7 @@ tablet_init_left_handed(struct evdev_device *device, WacomDevice *wacom)
 {
 	bool has_left_handed = true;
 
-#if HAVE_LIBWACOM
+#ifdef HAVE_LIBWACOM
 	has_left_handed = !wacom || libwacom_is_reversible(wacom);
 #endif
 	if (has_left_handed)
@@ -2798,7 +2798,7 @@ tablet_init_left_handed(struct evdev_device *device, WacomDevice *wacom)
 static inline bool
 tablet_is_display_tablet(WacomDevice *wacom)
 {
-#if HAVE_LIBWACOM
+#ifdef HAVE_LIBWACOM
 	return !wacom ||
 	       (libwacom_get_integration_flags(wacom) &
 		(WACOM_DEVICE_INTEGRATED_SYSTEM | WACOM_DEVICE_INTEGRATED_DISPLAY));
@@ -2810,7 +2810,7 @@ tablet_is_display_tablet(WacomDevice *wacom)
 static inline bool
 tablet_is_aes(struct evdev_device *device, WacomDevice *wacom)
 {
-#if HAVE_LIBWACOM
+#ifdef HAVE_LIBWACOM
 	int vid = evdev_device_get_id_vendor(device);
 	/* Wacom-specific check for whether smoothing is required:
 	 * libwacom keeps all the AES pens in a single group, so any device
@@ -2943,7 +2943,7 @@ tablet_init(struct tablet_dispatch *tablet, struct evdev_device *device)
 	enum libinput_tablet_tool_axis axis;
 	int rc = -1;
 	WacomDevice *wacom = NULL;
-#if HAVE_LIBWACOM
+#ifdef HAVE_LIBWACOM
 	WacomDeviceDatabase *db = libinput_libwacom_ref(li);
 	if (db) {
 		char event_path[64];
@@ -3018,7 +3018,7 @@ tablet_init(struct tablet_dispatch *tablet, struct evdev_device *device)
 
 	rc = 0;
 out:
-#if HAVE_LIBWACOM
+#ifdef HAVE_LIBWACOM
 	if (wacom)
 		libwacom_destroy(wacom);
 	if (db)
diff --git a/src/evdev-tablet.h b/src/evdev-tablet.h
index 88e8faf5..091a9de4 100644
--- a/src/evdev-tablet.h
+++ b/src/evdev-tablet.h
@@ -27,7 +27,7 @@
 
 #include "evdev.h"
 
-#if !HAVE_LIBWACOM
+#ifndef HAVE_LIBWACOM
 typedef void *WacomDevice;
 #endif
 
diff --git a/src/evdev.c b/src/evdev.c
index d0ef1c25..b5f860c9 100644
--- a/src/evdev.c
+++ b/src/evdev.c
@@ -48,7 +48,7 @@
 #include "linux/input.h"
 #include "quirks.h"
 
-#if HAVE_LIBWACOM
+#ifdef HAVE_LIBWACOM
 #include <libwacom/libwacom.h>
 #endif
 
diff --git a/src/libinput-plugin.c b/src/libinput-plugin.c
index 7e6aee94..0b43c76c 100644
--- a/src/libinput-plugin.c
+++ b/src/libinput-plugin.c
@@ -373,7 +373,7 @@ libinput_plugin_system_load_internal_plugins(struct libinput *libinput,
 
 	system->loaded = true;
 
-#if HAVE_MTDEV
+#ifdef HAVE_MTDEV
 	libinput_mtdev_plugin(libinput);
 #endif
 	libinput_tablet_plugin_forced_tool(libinput);
diff --git a/src/libinput-private.h b/src/libinput-private.h
index 4d6511dc..30ee5650 100644
--- a/src/libinput-private.h
+++ b/src/libinput-private.h
@@ -31,7 +31,7 @@
 #include <math.h>
 #include <stdarg.h>
 
-#if HAVE_LIBWACOM
+#ifdef HAVE_LIBWACOM
 #include <libwacom/libwacom.h>
 #endif
 
@@ -228,7 +228,7 @@ struct libinput {
 
 	struct libinput_plugin_system plugin_system;
 
-#if HAVE_LIBWACOM
+#ifdef HAVE_LIBWACOM
 	struct {
 		WacomDeviceDatabase *db;
 		size_t refcount;
@@ -1107,7 +1107,7 @@ point_in_rect(const struct device_coords *point, const struct device_coord_rect
 		point->y >= rect->y && point->y < rect->y + rect->h);
 }
 
-#if HAVE_LIBWACOM
+#ifdef HAVE_LIBWACOM
 WacomDeviceDatabase *
 libinput_libwacom_ref(struct libinput *li);
 void
diff --git a/src/libinput.c b/src/libinput.c
index 0602fff5..949780e8 100644
--- a/src/libinput.c
+++ b/src/libinput.c
@@ -5146,7 +5146,7 @@ libinput_tablet_tool_config_eraser_button_get_default_button(
 	return tool->config.eraser_button.get_button(tool);
 }
 
-#if HAVE_LIBWACOM
+#ifdef HAVE_LIBWACOM
 WacomDeviceDatabase *
 libinput_libwacom_ref(struct libinput *li)
 {
diff --git a/src/util-backtrace.h b/src/util-backtrace.h
index 7d1f0ff5..82462f02 100644
--- a/src/util-backtrace.h
+++ b/src/util-backtrace.h
@@ -54,7 +54,7 @@ backtrace_print(FILE *fp,
 		const char *highlight_before,
 		const char *highlight_extra)
 {
-#if HAVE_GSTACK
+#ifdef HAVE_GSTACK
 	pid_t parent, child;
 	int pipefd[2];
 
diff --git a/test/litest-main.c b/test/litest-main.c
index 8c059859..6fc31dac 100644
--- a/test/litest-main.c
+++ b/test/litest-main.c
@@ -47,7 +47,7 @@
 #include <unistd.h>
 
 #include "linux/input.h"
-#if HAVE_LIBSYSTEMD
+#ifdef HAVE_LIBSYSTEMD
 #include <systemd/sd-bus.h>
 #endif
 #ifdef __FreeBSD__
diff --git a/test/litest.c b/test/litest.c
index b419f440..2e0c16c3 100644
--- a/test/litest.c
+++ b/test/litest.c
@@ -47,7 +47,7 @@
 #include <unistd.h>
 
 #include "linux/input.h"
-#if HAVE_LIBSYSTEMD
+#ifdef HAVE_LIBSYSTEMD
 #include <systemd/sd-bus.h>
 #endif
 #ifdef __FreeBSD__
@@ -1615,7 +1615,7 @@ static inline int
 inhibit(void)
 {
 	int lock_fd = -1;
-#if HAVE_LIBSYSTEMD
+#ifdef HAVE_LIBSYSTEMD
 	_cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 	_unref_(sd_bus_message) *m = NULL;
 	_unref_(sd_bus) *bus = NULL;
diff --git a/test/test-pad.c b/test/test-pad.c
index de4d1854..6c3560d6 100644
--- a/test/test-pad.c
+++ b/test/test-pad.c
@@ -29,7 +29,7 @@
 #include <stdbool.h>
 #include <unistd.h>
 
-#if HAVE_LIBWACOM
+#ifdef HAVE_LIBWACOM
 #include <libwacom/libwacom.h>
 #endif
 
@@ -121,7 +121,7 @@ END_TEST
 
 START_TEST(pad_num_buttons_libwacom)
 {
-#if HAVE_LIBWACOM
+#ifdef HAVE_LIBWACOM
 	struct litest_device *dev = litest_current_device();
 	struct libinput_device *device = dev->libinput_device;
 	WacomDeviceDatabase *db = NULL;
@@ -172,7 +172,7 @@ END_TEST
 
 START_TEST(pad_button_intuos)
 {
-#if !HAVE_LIBWACOM
+#ifndef HAVE_LIBWACOM
 	struct litest_device *dev = litest_current_device();
 	struct libinput *li = dev->libinput;
 	unsigned int code;
@@ -231,7 +231,7 @@ END_TEST
 
 START_TEST(pad_button_bamboo)
 {
-#if !HAVE_LIBWACOM
+#ifndef HAVE_LIBWACOM
 	struct litest_device *dev = litest_current_device();
 	struct libinput *li = dev->libinput;
 	unsigned int code;
@@ -281,7 +281,7 @@ END_TEST
 
 START_TEST(pad_button_libwacom)
 {
-#if HAVE_LIBWACOM
+#ifdef HAVE_LIBWACOM
 	struct litest_device *dev = litest_current_device();
 	struct libinput *li = dev->libinput;
 	WacomDeviceDatabase *db = NULL;
@@ -325,7 +325,7 @@ START_TEST(pad_button_mode_groups)
 	struct libinput_event_tablet_pad *pev;
 	unsigned int expected_mode = 0;
 	int evdev_codes[KEY_OK - BTN_0] = { 0 };
-#if HAVE_LIBWACOM
+#ifdef HAVE_LIBWACOM
 	WacomDeviceDatabase *db = NULL;
 	WacomDevice *wacom = NULL;
 
@@ -703,7 +703,7 @@ END_TEST
 
 START_TEST(pad_left_handed_default)
 {
-#if HAVE_LIBWACOM
+#ifdef HAVE_LIBWACOM
 	struct litest_device *dev = litest_current_device();
 	struct libinput_device *device = dev->libinput_device;
 	enum libinput_config_status status;
@@ -735,7 +735,7 @@ START_TEST(pad_no_left_handed)
 	struct libinput_device *device = dev->libinput_device;
 
 	/* Without libwacom we default to left-handed being available */
-#if HAVE_LIBWACOM
+#ifdef HAVE_LIBWACOM
 	litest_assert(!libinput_device_config_left_handed_is_available(device));
 #else
 	litest_assert(libinput_device_config_left_handed_is_available(device));
@@ -744,7 +744,7 @@ START_TEST(pad_no_left_handed)
 	litest_assert_int_eq(libinput_device_config_left_handed_get_default(device), 0);
 	litest_assert_int_eq(libinput_device_config_left_handed_get(device), 0);
 
-#if HAVE_LIBWACOM
+#ifdef HAVE_LIBWACOM
 	enum libinput_config_status status;
 	status = libinput_device_config_left_handed_set(dev->libinput_device, 1);
 	litest_assert_enum_eq(status, LIBINPUT_CONFIG_STATUS_UNSUPPORTED);
@@ -763,7 +763,7 @@ END_TEST
 
 START_TEST(pad_left_handed_ring)
 {
-#if HAVE_LIBWACOM
+#ifdef HAVE_LIBWACOM
 	struct litest_device *dev = litest_current_device();
 	struct libinput *li = dev->libinput;
 	struct libinput_event *ev;
@@ -811,7 +811,7 @@ static bool
 pad_has_groups(struct litest_device *dev)
 {
 	bool rc = false;
-#if HAVE_LIBWACOM
+#ifdef HAVE_LIBWACOM
 	WacomDeviceDatabase *db = NULL;
 	WacomDevice *wacom = NULL;
 
@@ -1020,7 +1020,7 @@ END_TEST
 
 START_TEST(pad_mode_group_has_no_toggle)
 {
-#if HAVE_LIBWACOM
+#ifdef HAVE_LIBWACOM
 	struct litest_device *dev = litest_current_device();
 	struct libinput_device *device = dev->libinput_device;
 	struct libinput_tablet_pad_mode_group *group;
diff --git a/test/test-tablet.c b/test/test-tablet.c
index c99d4648..edca1e0f 100644
--- a/test/test-tablet.c
+++ b/test/test-tablet.c
@@ -31,7 +31,7 @@
 #include <stdbool.h>
 #include <unistd.h>
 
-#if HAVE_LIBWACOM
+#ifdef HAVE_LIBWACOM
 #include <libwacom/libwacom.h>
 #endif
 
@@ -1763,7 +1763,7 @@ END_TEST
 
 START_TEST(left_handed)
 {
-#if HAVE_LIBWACOM
+#ifdef HAVE_LIBWACOM
 	struct litest_device *dev = litest_current_device();
 	struct libinput *li = dev->libinput;
 	struct libinput_event *event;
@@ -1892,7 +1892,7 @@ START_TEST(no_left_handed)
 	struct litest_device *dev = litest_current_device();
 
 	/* Without libwacom we default to left-handed being available */
-#if HAVE_LIBWACOM
+#ifdef HAVE_LIBWACOM
 	litest_assert(
 		!libinput_device_config_left_handed_is_available(dev->libinput_device));
 #else
@@ -1904,7 +1904,7 @@ END_TEST
 
 START_TEST(left_handed_tilt)
 {
-#if HAVE_LIBWACOM
+#ifdef HAVE_LIBWACOM
 	struct litest_device *dev = litest_current_device();
 	struct libinput *li = dev->libinput;
 	struct libinput_event *event;
@@ -1977,7 +1977,7 @@ rotate_event(struct litest_device *dev, int angle_degrees)
 
 START_TEST(left_handed_mouse_rotation)
 {
-#if HAVE_LIBWACOM
+#ifdef HAVE_LIBWACOM
 	struct litest_device *dev = litest_current_device();
 	struct libinput *li = dev->libinput;
 	enum libinput_config_status status;
@@ -2023,7 +2023,7 @@ END_TEST
 
 START_TEST(left_handed_artpen_rotation)
 {
-#if HAVE_LIBWACOM
+#ifdef HAVE_LIBWACOM
 	struct litest_device *dev = litest_current_device();
 	struct libinput *li = dev->libinput;
 	struct libinput_event *event;
@@ -3542,7 +3542,7 @@ device_has_calibration(struct litest_device *dev)
 		libevdev_has_event_code(dev->evdev, EV_KEY, BTN_TOOL_PEN) ||
 		libevdev_has_event_code(dev->evdev, EV_KEY, BTN_STYLUS);
 
-#if HAVE_LIBWACOM
+#ifdef HAVE_LIBWACOM
 	WacomDeviceDatabase *db = libwacom_database_new();
 	if (db) {
 		WacomDevice *d =
@@ -6379,7 +6379,7 @@ START_TEST(touch_arbitration_swap_device)
 }
 END_TEST
 
-#if HAVE_LIBWACOM
+#ifdef HAVE_LIBWACOM
 static void
 verify_left_handed_tablet_motion(struct litest_device *tablet,
 				 struct libinput *li,
@@ -6502,7 +6502,7 @@ verify_left_handed_touch_sequence(struct litest_device *finger,
 
 START_TEST(tablet_rotation_left_handed)
 {
-#if HAVE_LIBWACOM
+#ifdef HAVE_LIBWACOM
 	struct litest_device *tablet = litest_current_device();
 	enum litest_device_type other;
 	struct litest_device *finger;
@@ -6545,7 +6545,7 @@ END_TEST
 
 START_TEST(tablet_rotation_left_handed_configuration)
 {
-#if HAVE_LIBWACOM
+#ifdef HAVE_LIBWACOM
 	struct litest_device *tablet = litest_current_device();
 	enum litest_device_type other;
 	struct litest_device *finger;
@@ -6597,7 +6597,7 @@ END_TEST
 
 START_TEST(tablet_rotation_left_handed_while_in_prox)
 {
-#if HAVE_LIBWACOM
+#ifdef HAVE_LIBWACOM
 	struct litest_device *tablet = litest_current_device();
 	enum litest_device_type other;
 	struct litest_device *finger;
@@ -6691,7 +6691,7 @@ END_TEST
 
 START_TEST(tablet_rotation_left_handed_while_touch_down)
 {
-#if HAVE_LIBWACOM
+#ifdef HAVE_LIBWACOM
 	struct litest_device *tablet = litest_current_device();
 	enum litest_device_type other;
 	struct litest_device *finger;
@@ -6752,7 +6752,7 @@ END_TEST
 
 START_TEST(tablet_rotation_left_handed_add_touchpad)
 {
-#if HAVE_LIBWACOM
+#ifdef HAVE_LIBWACOM
 	struct litest_device *tablet = litest_current_device();
 	enum litest_device_type other;
 	struct litest_device *finger;
@@ -6800,7 +6800,7 @@ END_TEST
 
 START_TEST(tablet_rotation_left_handed_add_tablet)
 {
-#if HAVE_LIBWACOM
+#ifdef HAVE_LIBWACOM
 	struct litest_device *finger = litest_current_device();
 	enum litest_device_type other;
 	struct litest_device *tablet;
@@ -7028,7 +7028,7 @@ END_TEST
 
 START_TEST(tablet_smoothing)
 {
-#if HAVE_LIBWACOM
+#ifdef HAVE_LIBWACOM
 	struct litest_device *dev = litest_current_device();
 	struct libinput *li = dev->libinput;
 	double x, y;
diff --git a/test/test-touch.c b/test/test-touch.c
index 331ec93e..a5071370 100644
--- a/test/test-touch.c
+++ b/test/test-touch.c
@@ -1353,7 +1353,7 @@ TEST_COLLECTION(touch)
 	litest_add(fake_mt_exists, LITEST_FAKE_MT, LITEST_ANY);
 	litest_add(fake_mt_no_touch_events, LITEST_FAKE_MT, LITEST_ANY);
 
-#if HAVE_MTDEV
+#ifdef HAVE_MTDEV
 	litest_add(touch_protocol_a_init, LITEST_PROTOCOL_A, LITEST_ANY);
 	litest_add(touch_protocol_a_touch, LITEST_PROTOCOL_A, LITEST_ANY);
 	litest_add(touch_protocol_a_2fg_touch, LITEST_PROTOCOL_A, LITEST_ANY);
@@ -1375,7 +1375,7 @@ TEST_COLLECTION(touch)
 
 	litest_add(touch_count_st, LITEST_SINGLE_TOUCH, LITEST_TOUCHPAD);
 	litest_add(touch_count_mt, LITEST_TOUCH, LITEST_SINGLE_TOUCH|LITEST_PROTOCOL_A);
-#if HAVE_MTDEV
+#ifdef HAVE_MTDEV
 	litest_add(touch_count_mtdev, LITEST_PROTOCOL_A, LITEST_ANY);
 	litest_add(touch_count_invalid, LITEST_ANY, LITEST_TOUCH|LITEST_SINGLE_TOUCH|LITEST_PROTOCOL_A);
 #endif
diff --git a/test/test-touchpad.c b/test/test-touchpad.c
index 8370bf34..eb9eae79 100644
--- a/test/test-touchpad.c
+++ b/test/test-touchpad.c
@@ -2573,7 +2573,7 @@ START_TEST(touchpad_left_handed_clickpad_delayed)
 }
 END_TEST
 
-#if HAVE_LIBWACOM
+#ifdef HAVE_LIBWACOM
 static inline bool
 touchpad_has_rotation(struct libevdev *evdev)
 {
@@ -2583,7 +2583,7 @@ touchpad_has_rotation(struct libevdev *evdev)
 
 START_TEST(touchpad_left_handed_rotation)
 {
-#if HAVE_LIBWACOM
+#ifdef HAVE_LIBWACOM
 	struct litest_device *dev = litest_current_device();
 	struct libinput_device *d = dev->libinput_device;
 	struct libinput *li = dev->libinput;
diff --git a/tools/libinput-debug-gui.c b/tools/libinput-debug-gui.c
index 2814edd0..0c2fcfc5 100644
--- a/tools/libinput-debug-gui.c
+++ b/tools/libinput-debug-gui.c
@@ -46,21 +46,21 @@
 
 #include "shared.h"
 
-#if HAVE_GTK_WAYLAND
+#ifdef HAVE_GTK_WAYLAND
 #include <wayland-client.h>
 
 #include "pointer-constraints-unstable-v1-client-protocol.h"
-#if HAVE_GTK4
+#ifdef HAVE_GTK4
 #include <gdk/wayland/gdkwayland.h>
 #else
 #include <gdk/gdkwayland.h>
 #endif
 #endif
 
-#if HAVE_GTK_X11
+#ifdef HAVE_GTK_X11
 #include <X11/X.h>
 #include <X11/Xlib.h>
-#if HAVE_GTK4
+#ifdef HAVE_GTK4
 #include <gdk/x11/gdkx.h>
 #else
 #include <gdk/gdkx.h>
@@ -119,7 +119,7 @@ struct window {
 	struct {
 		bool locked;
 
-#if HAVE_GTK_WAYLAND
+#ifdef HAVE_GTK_WAYLAND
 		struct zwp_pointer_constraints_v1 *wayland_pointer_constraints;
 		struct zwp_locked_pointer_v1 *wayland_locked_pointer;
 #endif
@@ -210,7 +210,7 @@ struct window {
 	struct libinput_device *devices[50];
 };
 
-#if HAVE_GTK_WAYLAND
+#ifdef HAVE_GTK_WAYLAND
 static void
 wayland_registry_global(void *data,
 			struct wl_registry *registry,
@@ -268,7 +268,7 @@ wayland_lock_pointer(struct window *w)
 	if (!w->lock_pointer.wayland_pointer_constraints)
 		return false;
 
-#if HAVE_GTK4
+#ifdef HAVE_GTK4
 	GtkNative *window = gtk_widget_get_native(w->win);
 	GdkSurface *gdk_surface = gtk_native_get_surface(window);
 	surface = gdk_wayland_surface_get_wl_surface(gdk_surface);
@@ -302,7 +302,7 @@ backend_is_wayland(void)
 }
 #endif /* HAVE_GTK_WAYLAND */
 
-#if HAVE_GTK_X11
+#ifdef HAVE_GTK_X11
 static bool
 x_lock_pointer(struct window *w)
 {
@@ -319,7 +319,7 @@ x_lock_pointer(struct window *w)
 	x_display = GDK_DISPLAY_XDISPLAY(gdk_display_get_default());
 #pragma GCC diagnostic pop
 
-#if HAVE_GTK4
+#ifdef HAVE_GTK4
 	GtkNative *window = gtk_widget_get_native(w->win);
 	GdkSurface *surface = gtk_native_get_surface(window);
 #pragma GCC diagnostic push
@@ -369,12 +369,12 @@ window_lock_pointer(struct window *w)
 	if (w->lock_pointer.locked)
 		return true;
 
-#if HAVE_GTK_WAYLAND
+#ifdef HAVE_GTK_WAYLAND
 	if (backend_is_wayland())
 		w->lock_pointer.locked = wayland_lock_pointer(w);
 #endif
 
-#if HAVE_GTK_X11
+#ifdef HAVE_GTK_X11
 	if (backend_is_x11())
 		w->lock_pointer.locked = x_lock_pointer(w);
 #endif
@@ -390,12 +390,12 @@ window_unlock_pointer(struct window *w)
 
 	w->lock_pointer.locked = false;
 
-#if HAVE_GTK_WAYLAND
+#ifdef HAVE_GTK_WAYLAND
 	if (backend_is_wayland())
 		wayland_unlock_pointer(w);
 #endif
 
-#if HAVE_GTK_X11
+#ifdef HAVE_GTK_X11
 	if (backend_is_x11())
 		x_unlock_pointer(w);
 #endif
@@ -1047,7 +1047,7 @@ draw(GtkWidget *widget, cairo_t *cr, gpointer data)
 	return TRUE;
 }
 
-#if HAVE_GTK4
+#ifdef HAVE_GTK4
 static void
 draw_gtk4(GtkDrawingArea *widget, cairo_t *cr, int width, int height, gpointer data)
 {
@@ -1058,7 +1058,7 @@ draw_gtk4(GtkDrawingArea *widget, cairo_t *cr, int width, int height, gpointer d
 static void
 window_place_ui_elements(GtkWidget *widget, struct window *w)
 {
-#if HAVE_GTK4
+#ifdef HAVE_GTK4
 	w->width = gtk_widget_get_width(w->area);
 	w->height = gtk_widget_get_height(w->area);
 #else
@@ -1089,7 +1089,7 @@ window_place_ui_elements(GtkWidget *widget, struct window *w)
 	w->pinch.y = w->height / 2;
 }
 
-#if HAVE_GTK4
+#ifdef HAVE_GTK4
 static void
 map_event_cb(GtkDrawingArea *widget, int width, int height, gpointer data)
 {
@@ -1131,7 +1131,7 @@ window_quit(struct window *w)
 	g_main_loop_quit(w->event_loop);
 }
 
-#if HAVE_GTK4
+#ifdef HAVE_GTK4
 static gboolean
 window_delete_event_cb(GtkWindow *window, gpointer data)
 {
@@ -1156,14 +1156,14 @@ window_init(struct window *w)
 {
 	list_init(&w->evdev_devices);
 
-#if HAVE_GTK4
+#ifdef HAVE_GTK4
 	w->win = gtk_window_new();
 #else
 	w->win = gtk_window_new(GTK_WINDOW_TOPLEVEL);
 #endif
 
 	if (getenv("LIBINPUT_RUNNING_TEST_SUITE")) {
-#if HAVE_GTK4
+#ifdef HAVE_GTK4
 		gtk_window_minimize(GTK_WINDOW(w->win));
 #else
 		gtk_window_iconify(GTK_WINDOW(w->win));
@@ -1178,7 +1178,7 @@ window_init(struct window *w)
 
 	w->area = gtk_drawing_area_new();
 
-#if HAVE_GTK4
+#ifdef HAVE_GTK4
 	g_signal_connect(G_OBJECT(w->area), "resize", G_CALLBACK(map_event_cb), w);
 	g_signal_connect(G_OBJECT(w->win),
 			 "close-request",
@@ -1929,7 +1929,7 @@ main(int argc, char **argv)
 	bool verbose = false;
 	bool gtk_init = false;
 
-#if HAVE_GTK4
+#ifdef HAVE_GTK4
 	gtk_init = gtk_init_check();
 #else
 	gtk_init = gtk_init_check(&argc, &argv);
diff --git a/tools/libinput-test.c b/tools/libinput-test.c
index 26aa73f6..27252734 100644
--- a/tools/libinput-test.c
+++ b/tools/libinput-test.c
@@ -31,7 +31,7 @@
 static inline void
 usage(void)
 {
-#if HAVE_INSTALLED_TESTS
+#ifdef HAVE_INSTALLED_TESTS
 	printf("Usage: libinput test [--help] <feature>\n");
 #else
 	fprintf(stderr, "libinput test was disabled in the build configuration\n");
diff --git a/tools/libinput-tool.c b/tools/libinput-tool.c
index 04316f34..f0937ff3 100644
--- a/tools/libinput-tool.c
+++ b/tools/libinput-tool.c
@@ -45,7 +45,7 @@ usage(void)
 	       "  debug-events\n"
 	       "	Print events to stdout\n"
 	       "\n"
-#if HAVE_DEBUG_GUI
+#ifdef HAVE_DEBUG_GUI
 	       "  debug-gui\n"
 	       "	Display a simple GUI to visualize libinput's events.\n"
 	       "\n"
diff --git a/udev/libinput-device-group.c b/udev/libinput-device-group.c
index 91e8a35b..cdb38c0b 100644
--- a/udev/libinput-device-group.c
+++ b/udev/libinput-device-group.c
@@ -30,7 +30,7 @@
 
 #include "libinput-util.h"
 
-#if HAVE_LIBWACOM
+#ifdef HAVE_LIBWACOM
 #include <libwacom/libwacom.h>
 
 static void
@@ -205,7 +205,7 @@ main(int argc, char **argv)
 	} else {
 		char *physmatch = NULL;
 
-#if HAVE_LIBWACOM
+#ifdef HAVE_LIBWACOM
 		if (vendor_id == VENDOR_ID_WACOM) {
 			if (product_id == PRODUCT_ID_WACOM_EKR)
 				wacom_handle_ekr(device,