diff --git a/src/librc/librc-misc.c b/src/librc/librc-misc.c
index 45bdb7ae..9d514bcd 100644
--- a/src/librc/librc-misc.c
+++ b/src/librc/librc-misc.c
@@ -19,6 +19,7 @@
 
 #include "queue.h"
 #include "librc.h"
+#include "helpers.h"
 
 bool
 rc_yesno(const char *value)
@@ -118,7 +119,7 @@ rc_getline(char **line, size_t *len, FILE *fp)
 librc_hidden_def(rc_getline)
 
 char *
-rc_proc_getent(const char *ent)
+rc_proc_getent(const char *ent _unused)
 {
 #ifdef __linux__
 	FILE *fp;
diff --git a/src/librc/librc.c b/src/librc/librc.c
index 3d3277db..84c76b5a 100644
--- a/src/librc/librc.c
+++ b/src/librc/librc.c
@@ -19,6 +19,7 @@ const char librc_copyright[] = "Copyright (c) 2007-2008 Roy Marples";
 
 #include "queue.h"
 #include "librc.h"
+#include <helpers.h>
 #ifdef __FreeBSD__
 #  include <sys/sysctl.h>
 #endif
@@ -232,7 +233,7 @@ detect_prefix(const char *systype)
 }
 
 static const char *
-detect_container(const char *systype)
+detect_container(const char *systype _unused)
 {
 #ifdef __FreeBSD__
 	if (systype) {
@@ -296,7 +297,7 @@ detect_container(const char *systype)
 }
 
 static const char *
-detect_vm(const char *systype)
+detect_vm(const char *systype _unused)
 {
 #ifdef __NetBSD__
 	if (systype) {
diff --git a/src/rc/start-stop-daemon.c b/src/rc/start-stop-daemon.c
index eb5b4f7a..b1c6e73d 100644
--- a/src/rc/start-stop-daemon.c
+++ b/src/rc/start-stop-daemon.c
@@ -64,6 +64,7 @@ static struct pam_conv conv = { NULL, NULL};
 #include "rc.h"
 #include "rc-misc.h"
 #include "_usage.h"
+#include "helpers.h"
 
 const char *applet = NULL;
 const char *extraopts = NULL;
@@ -153,7 +154,9 @@ extern char **environ;
 # define SYS_ioprio_set __NR_ioprio_set
 #endif
 #if !defined(__DragonFly__)
-static inline int ioprio_set(int which, int who, int ioprio)
+static inline int ioprio_set(int which _unused,
+			     int who _unused,
+			     int ioprio _unused)
 {
 #ifdef SYS_ioprio_set
 	return syscall(SYS_ioprio_set, which, who, ioprio);
diff --git a/src/rc/supervise-daemon.c b/src/rc/supervise-daemon.c
index a47e47d9..57d55194 100644
--- a/src/rc/supervise-daemon.c
+++ b/src/rc/supervise-daemon.c
@@ -62,6 +62,7 @@ static struct pam_conv conv = { NULL, NULL};
 #include "rc.h"
 #include "rc-misc.h"
 #include "_usage.h"
+#include "helpers.h"
 
 const char *applet = NULL;
 const char *extraopts = NULL;
@@ -124,7 +125,8 @@ extern char **environ;
 # define SYS_ioprio_set __NR_ioprio_set
 #endif
 #if !defined(__DragonFly__)
-static inline int ioprio_set(int which, int who, int ioprio)
+static inline int ioprio_set(int which _unused, int who _unused,
+			     int ioprio _unused)
 {
 #ifdef SYS_ioprio_set
 	return syscall(SYS_ioprio_set, which, who, ioprio);