diff --git a/client/pool-buffer.c b/client/pool-buffer.c
index fa468c0d..588bd06c 100644
--- a/client/pool-buffer.c
+++ b/client/pool-buffer.c
@@ -1,4 +1,4 @@
-#define _XOPEN_SOURCE 500
+#define _POSIX_C_SOURCE 200809
 #include <assert.h>
 #include <cairo/cairo.h>
 #include <fcntl.h>
diff --git a/meson.build b/meson.build
index eb5cba84..253a4e96 100644
--- a/meson.build
+++ b/meson.build
@@ -38,7 +38,7 @@ pango          = dependency('pango')
 pangocairo     = dependency('pangocairo')
 gdk_pixbuf     = dependency('gdk-pixbuf-2.0', required: false)
 pixman         = dependency('pixman-1')
-libcap         = dependency('libcap')
+libcap         = dependency('libcap', required: false)
 libinput       = dependency('libinput', version: '>=1.6.0')
 libpam         = cc.find_library('pam')
 systemd        = dependency('libsystemd', required: false)
@@ -104,7 +104,7 @@ if scdoc.found()
 	endforeach
 endif
 
-add_project_arguments('-DSYSCONFDIR="/@0@"'.format(sysconfdir), language : 'c')
+add_project_arguments('-DSYSCONFDIR="/@0@/@1@"'.format(prefix, sysconfdir), language : 'c')
 
 version = get_option('sway-version')
 if version != ''
diff --git a/sway/commands.c b/sway/commands.c
index 359856cc..e72b8916 100644
--- a/sway/commands.c
+++ b/sway/commands.c
@@ -1,4 +1,4 @@
-#define _XOPEN_SOURCE 500
+#define _POSIX_C_SOURCE 200809
 #include <ctype.h>
 #include <stdarg.h>
 #include <stdlib.h>
diff --git a/sway/commands/bar.c b/sway/commands/bar.c
index f6a70c17..f760888e 100644
--- a/sway/commands/bar.c
+++ b/sway/commands/bar.c
@@ -1,4 +1,4 @@
-#define _XOPEN_SOURCE 500
+#define _POSIX_C_SOURCE 200809
 #include <string.h>
 #include <strings.h>
 #include <wlr/util/log.h>
diff --git a/sway/commands/output/background.c b/sway/commands/output/background.c
index 74894812..ddad679d 100644
--- a/sway/commands/output/background.c
+++ b/sway/commands/output/background.c
@@ -1,4 +1,4 @@
-#define _XOPEN_SOURCE 500
+#define _POSIX_C_SOURCE 200809
 #include <libgen.h>
 #include <strings.h>
 #include <unistd.h>
diff --git a/sway/main.c b/sway/main.c
index 7ed10c86..2f05dc38 100644
--- a/sway/main.c
+++ b/sway/main.c
@@ -366,13 +366,15 @@ int main(int argc, char **argv) {
 		return 1;
 	}
 
-#ifdef __linux__
+#if defined(__linux__) || defined(__FreeBSD__)
 	if (getuid() != geteuid() || getgid() != getegid()) {
+#ifdef __linux__
 		// Retain capabilities after setuid()
 		if (prctl(PR_SET_KEEPCAPS, 1, 0, 0, 0)) {
 			wlr_log(WLR_ERROR, "Cannot keep caps after setuid()");
 			exit(EXIT_FAILURE);
 		}
+#endif
 		suid = true;
 	}
 #endif
@@ -382,7 +384,7 @@ int main(int argc, char **argv) {
 	detect_proprietary();
 	detect_raspi();
 
-#ifdef __linux__
+#if defined(__linux__) || defined(__FreeBSD__)
 	drop_permissions(suid);
 #endif
 	// handle SIGTERM signals
diff --git a/sway/server.c b/sway/server.c
index 8b5bc93c..749365cb 100644
--- a/sway/server.c
+++ b/sway/server.c
@@ -140,6 +140,10 @@ bool server_init(struct sway_server *server) {
 
 void server_fini(struct sway_server *server) {
 	// TODO: free sway-specific resources
+#ifdef HAVE_XWAYLAND
+	wlr_xwayland_destroy(server->xwayland.wlr_xwayland);
+#endif
+	wl_display_destroy_clients(server->wl_display);
 	wl_display_destroy(server->wl_display);
 	list_free(server->dirty_containers);
 	list_free(server->transactions);
diff --git a/sway/tree/workspace.c b/sway/tree/workspace.c
index 60256336..1957d94f 100644
--- a/sway/tree/workspace.c
+++ b/sway/tree/workspace.c
@@ -1,4 +1,4 @@
-#define _XOPEN_SOURCE 500
+#define _POSIX_C_SOURCE 200809
 #include <ctype.h>
 #include <limits.h>
 #include <stdbool.h>
diff --git a/swaybar/ipc.c b/swaybar/ipc.c
index c2d05920..0e60c10c 100644
--- a/swaybar/ipc.c
+++ b/swaybar/ipc.c
@@ -1,4 +1,4 @@
-#define _XOPEN_SOURCE 500
+#define _POSIX_C_SOURCE 200809
 #include <limits.h>
 #include <string.h>
 #include <strings.h>
diff --git a/swaylock/meson.build b/swaylock/meson.build
index 63f694b9..675b8c69 100644
--- a/swaylock/meson.build
+++ b/swaylock/meson.build
@@ -24,7 +24,16 @@ executable(
 	install: true
 )
 
-install_data(
-	'pam/swaylock',
-	install_dir: sysconfdir + '/pam.d/'
-)
+if is_freebsd
+	install_data(
+		'pam/swaylock.freebsd',
+		install_dir: sysconfdir + '/pam.d/',
+		rename: 'swaylock'
+	)
+else
+	install_data(
+		'pam/swaylock.linux',
+		install_dir: sysconfdir + '/pam.d/',
+		rename: 'swaylock'
+	)
+endif
diff --git a/swaylock/pam/swaylock.freebsd b/swaylock/pam/swaylock.freebsd
new file mode 100644
index 00000000..603fc185
--- /dev/null
+++ b/swaylock/pam/swaylock.freebsd
@@ -0,0 +1,6 @@
+#
+# PAM configuration file for the swaylock screen locker. By default, it includes
+# the 'passwd' configuration file (see /etc/pam.d/passwd)
+#
+
+auth include passwd
diff --git a/swaylock/pam/swaylock b/swaylock/pam/swaylock.linux
similarity index 100%
rename from swaylock/pam/swaylock
rename to swaylock/pam/swaylock.linux