diff --git a/sys/compat/linux/linux_mib.c b/sys/compat/linux/linux_mib.c
index 5e770f63c480..1bb8bb758be6 100644
--- a/sys/compat/linux/linux_mib.c
+++ b/sys/compat/linux/linux_mib.c
@@ -69,6 +69,10 @@ static unsigned linux_osd_jail_slot;
 SYSCTL_NODE(_compat, OID_AUTO, linux, CTLFLAG_RW, 0,
 	    "Linux mode");
 
+static int	linux_set_osname(struct thread *td, char *osname);
+static int	linux_set_osrelease(struct thread *td, char *osrelease);
+static int	linux_set_oss_version(struct thread *td, int oss_version);
+
 static int
 linux_sysctl_osname(SYSCTL_HANDLER_ARGS)
 {
@@ -469,7 +473,7 @@ linux_get_osname(struct thread *td, char *dst)
 	mtx_unlock(&pr->pr_mtx);
 }
 
-int
+static int
 linux_set_osname(struct thread *td, char *osname)
 {
 	struct prison *pr;
@@ -505,7 +509,7 @@ linux_kernver(struct thread *td)
 	return (osrel);
 }
 
-int
+static int
 linux_set_osrelease(struct thread *td, char *osrelease)
 {
 	struct prison *pr;
@@ -533,7 +537,7 @@ linux_get_oss_version(struct thread *td)
 	return (version);
 }
 
-int
+static int
 linux_set_oss_version(struct thread *td, int oss_version)
 {
 	struct prison *pr;
diff --git a/sys/compat/linux/linux_mib.h b/sys/compat/linux/linux_mib.h
index f78a5e501402..e8eedf906443 100644
--- a/sys/compat/linux/linux_mib.h
+++ b/sys/compat/linux/linux_mib.h
@@ -35,13 +35,10 @@ void	linux_osd_jail_register(void);
 void	linux_osd_jail_deregister(void);
 
 void	linux_get_osname(struct thread *td, char *dst);
-int	linux_set_osname(struct thread *td, char *osname);
 
 void	linux_get_osrelease(struct thread *td, char *dst);
-int	linux_set_osrelease(struct thread *td, char *osrelease);
 
 int	linux_get_oss_version(struct thread *td);
-int	linux_set_oss_version(struct thread *td, int oss_version);
 
 int	linux_kernver(struct thread *td);