diff --git a/include/grp.h b/include/grp.h
index 8ac0371d9190..e8a0702af452 100644
--- a/include/grp.h
+++ b/include/grp.h
@@ -70,7 +70,7 @@ int setgrent __P((void));
 void endgrent __P((void));
 void setgrfile __P((const char *));
 int setgroupent __P((int));
-char	*group_from_gid __P((gid_t, int));
+const char *group_from_gid __P((gid_t, int));
 #endif
 __END_DECLS
 
diff --git a/include/pwd.h b/include/pwd.h
index 9a9398da25be..ca8c42fcaf66 100644
--- a/include/pwd.h
+++ b/include/pwd.h
@@ -106,7 +106,7 @@ struct passwd	*getpwent __P((void));
 int		 setpassent __P((int));
 void		 setpwent __P((void));
 void		 endpwent __P((void));
-char		*user_from_uid __P((uid_t, int));
+const char	*user_from_uid __P((uid_t, int));
 #endif
 __END_DECLS
 
diff --git a/lib/libc/gen/pwcache.3 b/lib/libc/gen/pwcache.3
index eb2f9e08bf41..dc8c77c653ac 100644
--- a/lib/libc/gen/pwcache.3
+++ b/lib/libc/gen/pwcache.3
@@ -42,10 +42,10 @@
 .Lb libc
 .Sh SYNOPSIS
 .In pwd.h
-.Ft char *
+.Ft const char *
 .Fn user_from_uid "unsigned long uid" "int nouser"
 .In grp.h
-.Ft char *
+.Ft const char *
 .Fn group_from_gid "unsigned long gid" "int nogroup"
 .Sh DESCRIPTION
 The
diff --git a/lib/libc/gen/pwcache.c b/lib/libc/gen/pwcache.c
index e5ed90bc081f..cb2aa42123de 100644
--- a/lib/libc/gen/pwcache.c
+++ b/lib/libc/gen/pwcache.c
@@ -48,7 +48,7 @@ __FBSDID("$FreeBSD$");
 #define	NCACHE	64			/* power of 2 */
 #define	MASK	(NCACHE - 1)		/* bits to store with */
 
-char *
+const char *
 user_from_uid(uid_t uid, int nouser)
 {
 	static struct ncache {
@@ -82,7 +82,7 @@ user_from_uid(uid_t uid, int nouser)
 	return ((nouser && !cp->found) ? NULL : cp->name);
 }
 
-char *
+const char *
 group_from_gid(gid_t gid, int nogroup)
 {
 	static struct ncache {