diff --git a/src/api.c b/src/api.c
index d896d8df..69b2f228 100644
--- a/src/api.c
+++ b/src/api.c
@@ -59,6 +59,8 @@ static int call(int (*action)(svc_t *, void *), char *buf, size_t len)
 
 static int stop(svc_t *svc, void *user_data)
 {
+	(void)user_data;
+
 	if (!svc)
 		return 1;
 
@@ -72,6 +74,8 @@ static int stop(svc_t *svc, void *user_data)
 
 static int start(svc_t *svc, void *user_data)
 {
+	(void)user_data;
+
 	if (!svc)
 		return 1;
 
@@ -105,6 +109,8 @@ static int restart(svc_t *svc, void *user_data)
 
 static int reload(svc_t *svc, void *user_data)
 {
+	(void)user_data;
+
 	if (!svc)
 		return 1;
 
@@ -149,6 +155,8 @@ static int missing(char *job, char *id, void *user_data)
 {
 	char buf[20];
 
+	(void)user_data;
+
 	if (!job)
 		job = "";
 	if (!id)
@@ -228,6 +236,8 @@ struct wq emergency = { .cb = bypass_shutdown };
 
 static void bypass_shutdown(void *unused)
 {
+	(void)unused;
+
 	cprintf("TIMEOUT TIMEOUT SHUTTING DOWN NOW!!\n");
 	do_shutdown(halt);
 }
@@ -332,6 +342,8 @@ static void api_cb(uev_t *w, void *arg, int events)
 	int sd, lvl;
 	svc_t *svc;
 
+	(void)arg;
+
 	if (UEV_ERROR == events) {
 		dbg("%s(): api socket %d invalid.", __func__, w->fd);
 		goto error;
diff --git a/src/cgroup.c b/src/cgroup.c
index ca886d7b..0c7e3155 100644
--- a/src/cgroup.c
+++ b/src/cgroup.c
@@ -267,6 +267,7 @@ static void cgroup_events_cb(uev_t *w, void *arg, int events)
 	ssize_t sz;
 	size_t off;
 
+	(void)arg;
 	if (UEV_ERROR == events) {
 		dbg("%s(): inotify socket %d invalid.", __func__, w->fd);
 		return;
diff --git a/src/cond-w.c b/src/cond-w.c
index facc57c9..faf72e2f 100644
--- a/src/cond-w.c
+++ b/src/cond-w.c
@@ -202,6 +202,9 @@ static int do_delete(const char *fpath, const struct stat *sb, int tflag, struct
 {
 	const char *cond, *ptr;
 
+	(void)sb;
+	(void)tflag;
+
 	if (ftw->level == 0)
 		return 1;
 
@@ -390,6 +393,8 @@ static int do_assert(const char *fpath, const struct stat *sb, int tflg, struct
 {
 	char *nm;
 
+	(void)sb;
+
 	if (ftw->level == 0)
 		return 1;
 
diff --git a/src/conf.c b/src/conf.c
index ea2e4f3d..6f277b2a 100644
--- a/src/conf.c
+++ b/src/conf.c
@@ -1562,6 +1562,8 @@ static int conf_iwatch_read(int fd)
 
 static void conf_cb(uev_t *w, void *arg, int events)
 {
+	(void)arg;
+
 	if (UEV_ERROR == events) {
 		dbg("%s(): iwatch socket %d invalid.", __func__, w->fd);
 		return;
diff --git a/src/devmon.c b/src/devmon.c
index fda09605..2960757b 100644
--- a/src/devmon.c
+++ b/src/devmon.c
@@ -164,6 +164,8 @@ static void devmon_scandir(struct iwatch *iw, char *dir, int len)
 	size_t i;
 	int rc;
 
+	(void)iw;
+
 	snprintf(path, sizeof(path), "%s/*", dir);
 	rc = glob(path, GLOB_NOSORT, NULL, &gl);
 	if (rc && rc != GLOB_NOMATCH)
@@ -207,6 +209,8 @@ static void devmon_cb(uev_t *w, void *arg, int events)
 	ssize_t sz;
 	size_t off;
 
+	(void)arg;
+
 	sz = read(w->fd, ev_buf, sizeof(ev_buf) - 1);
 	if (sz <= 0) {
 		err(1, "invalid inotify event");
diff --git a/src/helpers.c b/src/helpers.c
index a15d66af..9129679c 100644
--- a/src/helpers.c
+++ b/src/helpers.c
@@ -293,6 +293,8 @@ static size_t print_timestamp(char *buf, size_t len)
 	sscanf(buf, "%f %f", &stamp, &dummy);
 	return snprintf(buf, len, "[ %.6f ]", stamp);
 #else
+	(void)buf;
+	(void)len;
 	return 0;
 #endif
 }
diff --git a/src/plugin.c b/src/plugin.c
index 17d63afe..a155d5d9 100644
--- a/src/plugin.c
+++ b/src/plugin.c
@@ -320,6 +320,8 @@ static int init_plugins(uev_ctx_t *ctx)
 	plugin_t *p, *tmp;
 	int fail = 0;
 
+	(void)ctx;
+
 	PLUGIN_ITERATOR(p, tmp) {
 		if (plugin_io_init(p))
 			fail++;
diff --git a/src/service.c b/src/service.c
index 83d9aa60..f14378a3 100644
--- a/src/service.c
+++ b/src/service.c
@@ -2823,6 +2823,7 @@ void service_step_all(int types)
 
 void service_worker(void *unused)
 {
+	(void)unused;
 	service_step_all(SVC_TYPE_RESPAWN | SVC_TYPE_RUNTASK);
 }
 
diff --git a/src/sig.c b/src/sig.c
index ffbe7faf..080ea305 100644
--- a/src/sig.c
+++ b/src/sig.c
@@ -260,6 +260,7 @@ static int status_cb(int pid, void *data)
 {
 	int *has_proc = (int *)data;
 
+	(void)pid;
 	*has_proc = 1;
 
 	return 1;
@@ -425,6 +426,8 @@ void do_shutdown(shutop_t op)
  */
 static void sighup_cb(uev_t *w, void *arg, int events)
 {
+	(void)arg;
+
 	dbg("...");
 	if (UEV_ERROR == events) {
 		errx(1, "Unrecoverable error in signal watcher");
@@ -451,6 +454,9 @@ static void sighup_cb(uev_t *w, void *arg, int events)
  */
 static void sigint_cb(uev_t *w, void *arg, int events)
 {
+	(void)w;
+	(void)arg;
+
 	dbg("...");
 	if (UEV_ERROR == events) {
 		errx(1, "Unrecoverable error in signal watcher");
@@ -467,6 +473,9 @@ static void sigint_cb(uev_t *w, void *arg, int events)
  */
 static void sigpwr_cb(uev_t *w, void *arg, int events)
 {
+	(void)w;
+	(void)arg;
+
 	dbg("...");
 	if (UEV_ERROR == events) {
 		errx(1, "Unrecoverable error in signal watcher");
@@ -481,6 +490,8 @@ static void sigpwr_cb(uev_t *w, void *arg, int events)
  */
 static void sigusr1_cb(uev_t *w, void *arg, int events)
 {
+	(void)arg;
+
 	dbg("...");
 	if (UEV_ERROR == events) {
 		errx(1, "Unrecoverable error in signal watcher");
@@ -502,6 +513,9 @@ static void sigusr1_cb(uev_t *w, void *arg, int events)
  */
 static void sigusr2_cb(uev_t *w, void *arg, int events)
 {
+	(void)w;
+	(void)arg;
+
 	dbg("...");
 	if (UEV_ERROR == events) {
 		errx(1, "Unrecoverable error in signal watcher");
@@ -522,6 +536,9 @@ static void sigusr2_cb(uev_t *w, void *arg, int events)
  */
 static void sigterm_cb(uev_t *w, void *arg, int events)
 {
+	(void)w;
+	(void)arg;
+
 	dbg("...");
 	if (UEV_ERROR == events) {
 		errx(1, "Unrecoverable error in signal watcher");
@@ -545,6 +562,9 @@ static void sigchld_cb(uev_t *w, void *arg, int events)
 	int status;
 	pid_t pid;
 
+	(void)w;
+	(void)arg;
+
 	if (UEV_ERROR == events) {
 		errx(1, "Unrecoverable error in signal watcher");
 		return;
@@ -601,6 +621,9 @@ const char *sig_name(int signo)
  */
 static void chld_handler(int sig, siginfo_t *info, void *ctx)
 {
+	(void)sig;
+	(void)info;
+	(void)ctx;
 	/* NOP */
 }
 
diff --git a/src/tmpfiles.c b/src/tmpfiles.c
index 8bd0d34c..ab68e233 100644
--- a/src/tmpfiles.c
+++ b/src/tmpfiles.c
@@ -114,6 +114,9 @@ static int parse_mm(char *arg, int *major, int *minor)
 
 static int do_delete(const char *fpath, const struct stat *sb, int tflag, struct FTW *ftw)
 {
+	(void)sb;
+	(void)tflag;
+
 	if (ftw->level == 0)
 		return 1;