diff --git a/include/wlr/types/wlr_keyboard.h b/include/wlr/types/wlr_keyboard.h
index af205c63..97517cbe 100644
--- a/include/wlr/types/wlr_keyboard.h
+++ b/include/wlr/types/wlr_keyboard.h
@@ -6,13 +6,25 @@
 #include <wayland-server.h>
 #include <xkbcommon/xkbcommon.h>
 
-enum WLR_KEYBOARD_LED {
+enum wlr_keyboard_led {
 	WLR_LED_NUM_LOCK = 1,
 	WLR_LED_CAPS_LOCK = 2,
 	WLR_LED_SCROLL_LOCK = 4,
 	WLR_LED_LAST
 };
 
+enum wlr_keyboard_modifier {
+	WLR_MODIFIER_SHIFT = 1,
+	WLR_MODIFIER_CAPS = 2,
+	WLR_MODIFIER_CTRL = 4,
+	WLR_MODIFIER_ALT = 8,
+	WLR_MODIFIER_MOD2 = 16,
+	WLR_MODIFIER_MOD3 = 32,
+	WLR_MODIFIER_LOGO = 64,
+	WLR_MODIFIER_MOD5 = 128,
+	WLR_MODIFIER_LAST
+};
+
 struct wlr_keyboard_impl;
 
 struct wlr_keyboard {
@@ -23,7 +35,15 @@ struct wlr_keyboard {
 	size_t keymap_size;
 	struct xkb_keymap *keymap;
 	struct xkb_state *xkb_state;
-	xkb_led_index_t leds[WLR_LED_LAST];
+	xkb_led_index_t led_indexes[WLR_LED_LAST];
+	xkb_mod_index_t mod_indexes[WLR_MODIFIER_LAST];
+
+	struct {
+		xkb_mod_mask_t depressed;
+		xkb_mod_mask_t latched;
+		xkb_mod_mask_t locked;
+		xkb_mod_mask_t group;
+	} modifiers;
 
 	struct {
 		struct wl_signal key;
@@ -48,6 +68,6 @@ struct wlr_event_keyboard_key {
 };
 
 void wlr_keyboard_set_keymap(struct wlr_keyboard *kb,
-		struct xkb_keymap *keymap);
+	struct xkb_keymap *keymap);
 
 #endif
diff --git a/types/wlr_keyboard.c b/types/wlr_keyboard.c
index b356f63a..dc3b8f8e 100644
--- a/types/wlr_keyboard.c
+++ b/types/wlr_keyboard.c
@@ -13,19 +13,45 @@ int os_create_anonymous_file(off_t size);
 static void keyboard_led_update(struct wlr_keyboard *keyboard) {
 	uint32_t leds = 0;
 	for (uint32_t i = 0; i < WLR_LED_LAST; ++i) {
-		if (xkb_state_led_index_is_active(keyboard->xkb_state, keyboard->leds[i])) {
+		if (xkb_state_led_index_is_active(keyboard->xkb_state,
+				keyboard->led_indexes[i])) {
 			leds |= (1 << i);
 		}
 	}
 	wlr_keyboard_led_update(keyboard, leds);
 }
 
+static void keyboard_modifier_update(struct wlr_keyboard *keyboard) {
+	xkb_mod_mask_t depressed = xkb_state_serialize_mods(keyboard->xkb_state,
+		XKB_STATE_DEPRESSED);
+	xkb_mod_mask_t latched = xkb_state_serialize_mods(keyboard->xkb_state,
+		XKB_STATE_LATCHED);
+	xkb_mod_mask_t locked = xkb_state_serialize_mods(keyboard->xkb_state,
+		XKB_STATE_LOCKED);
+	xkb_mod_mask_t group = xkb_state_serialize_layout(keyboard->xkb_state,
+		XKB_STATE_LAYOUT_EFFECTIVE);
+	if (depressed == keyboard->modifiers.depressed &&
+			latched == keyboard->modifiers.latched &&
+			locked == keyboard->modifiers.locked &&
+			group == keyboard->modifiers.group) {
+		return;
+	}
+
+	keyboard->modifiers.depressed = depressed;
+	keyboard->modifiers.latched = latched;
+	keyboard->modifiers.locked = locked;
+	keyboard->modifiers.group = group;
+
+	// TODO: wl_keyboard_send_modifiers
+}
+
 void wlr_keyboard_update_state(struct wlr_keyboard *keyboard,
 		struct wlr_event_keyboard_key *event) {
 	uint32_t keycode = event->keycode + 8;
 	xkb_state_update_key(keyboard->xkb_state, keycode,
-		event->state == WLR_KEY_PRESSED ?  XKB_KEY_DOWN : XKB_KEY_UP);
+		event->state == WLR_KEY_PRESSED ? XKB_KEY_DOWN : XKB_KEY_UP);
 	keyboard_led_update(keyboard);
+	keyboard_modifier_update(keyboard);
 	wl_signal_emit(&keyboard->events.key, event);
 }
 
@@ -57,21 +83,39 @@ void wlr_keyboard_set_keymap(struct wlr_keyboard *kb,
 	wlr_log(L_DEBUG, "Keymap set");
 	kb->keymap = keymap;
 	assert(kb->xkb_state = xkb_state_new(kb->keymap));
-	const char *led_names[3] = {
+
+	const char *led_names[WLR_LED_LAST] = {
 		XKB_LED_NAME_NUM,
 		XKB_LED_NAME_CAPS,
 		XKB_LED_NAME_SCROLL
 	};
-	for (uint32_t i = 0; i < 3; ++i) {
-		kb->leds[i] = xkb_map_led_get_index(kb->keymap, led_names[i]);
+	for (size_t i = 0; i < WLR_LED_LAST; ++i) {
+		kb->led_indexes[i] = xkb_map_led_get_index(kb->keymap, led_names[i]);
 	}
+
+	const char *mod_names[WLR_MODIFIER_LAST] = {
+		XKB_MOD_NAME_SHIFT,
+		XKB_MOD_NAME_CAPS,
+		XKB_MOD_NAME_CTRL, // "Control"
+		XKB_MOD_NAME_ALT, // "Mod1"
+		XKB_MOD_NAME_NUM, // "Mod2"
+		"Mod3",
+		XKB_MOD_NAME_LOGO, // "Mod4"
+		"Mod5",
+	};
+	// TODO: there's also "Ctrl", "Alt"?
+	for (size_t i = 0; i < WLR_LED_LAST; ++i) {
+		kb->mod_indexes[i] = xkb_map_mod_get_index(kb->keymap, mod_names[i]);
+	}
+
 	char *keymap_str = xkb_keymap_get_as_string(kb->keymap,
 		XKB_KEYMAP_FORMAT_TEXT_V1);
 	kb->keymap_size = strlen(keymap_str) + 1;
 	kb->keymap_fd = os_create_anonymous_file(kb->keymap_size);
 	void *ptr = mmap(NULL, kb->keymap_size,
-			PROT_READ | PROT_WRITE, MAP_SHARED, kb->keymap_fd, 0);
+		PROT_READ | PROT_WRITE, MAP_SHARED, kb->keymap_fd, 0);
 	strcpy(ptr, keymap_str);
 	free(keymap_str);
+
 	wl_signal_emit(&kb->events.keymap, kb);
 }