diff --git a/include/time.h b/include/time.h
index 60cc0f44..161d006f 100644
--- a/include/time.h
+++ b/include/time.h
@@ -59,7 +59,7 @@ struct timespec
 int clock_gettime (clockid_t clk_id, struct timespec *tp);
 struct tm *localtime (time_t const *timep);
 struct tm *gmtime (time_t const *time);
-int mktime (struct tm *broken_time);
+time_t mktime (struct tm *broken_time);
 int nanosleep (struct timespec const *requested_time, struct timespec const *remaining);
 time_t time (time_t * tloc);
 
diff --git a/lib/stub/getgrgid.c b/lib/stub/getgrgid.c
index 9859b8dd..88898714 100644
--- a/lib/stub/getgrgid.c
+++ b/lib/stub/getgrgid.c
@@ -19,6 +19,7 @@
  */
 
 #include <mes/lib.h>
+#include <errno.h>
 #include <grp.h>
 
 struct group *
@@ -27,8 +28,13 @@ getgrgid (gid_t gid)
   static int stub = 0;
   if (__mes_debug () && !stub)
     eputs ("getgrid stub\n");
-  static char *groups[2] = {"root", 0 };
-  static struct group root = {"root", 0, groups};
+  static char *groups[2] = { "root", 0 };
+#if SYSTEM_LIBC
+  static struct group root = { "root", 0, 0 };
+  root.gr_mem = groups;
+#else
+  static struct group root = { "root", 0, groups };
+#endif
   stub = 1;
   errno = 0;
   return &root;
diff --git a/lib/stub/getgrnam.c b/lib/stub/getgrnam.c
index 466d738e..4efde888 100644
--- a/lib/stub/getgrnam.c
+++ b/lib/stub/getgrnam.c
@@ -19,6 +19,7 @@
  */
 
 #include <mes/lib.h>
+#include <errno.h>
 #include <grp.h>
 
 struct group *
@@ -27,8 +28,13 @@ getgrnam (char const *name)
   static int stub = 0;
   if (__mes_debug () && !stub)
     eputs ("getgrid stub\n");
-  static char *groups[2] = {"root", 0 };
-  static struct group root = {"root", 0, groups};
+  static char *groups[2] = { "root", 0 };
+#if SYSTEM_LIBC
+  static struct group root = { "root", 0, 0 };
+  root.gr_mem = groups;
+#else
+  static struct group root = { "root", 0, groups };
+#endif
   stub = 1;
   errno = 0;
   return &root;
diff --git a/lib/stub/getpgid.c b/lib/stub/getpgid.c
index f82d3c5e..8ad82ee2 100644
--- a/lib/stub/getpgid.c
+++ b/lib/stub/getpgid.c
@@ -19,6 +19,7 @@
  */
 
 #include <mes/lib.h>
+#include <errno.h>
 #include <unistd.h>
 
 int
diff --git a/lib/stub/getpgrp.c b/lib/stub/getpgrp.c
index 7b7510b1..a9ddcaae 100644
--- a/lib/stub/getpgrp.c
+++ b/lib/stub/getpgrp.c
@@ -19,6 +19,7 @@
  */
 
 #include <mes/lib.h>
+#include <errno.h>
 #include <unistd.h>
 
 pid_t
diff --git a/lib/stub/mktime.c b/lib/stub/mktime.c
index 65e49acf..093d73b6 100644
--- a/lib/stub/mktime.c
+++ b/lib/stub/mktime.c
@@ -19,9 +19,10 @@
  */
 
 #include <mes/lib.h>
+#include <errno.h>
 #include <time.h>
 
-int
+time_t
 mktime (struct tm *broken_time)
 {
   static int stub = 0;
diff --git a/lib/stub/setgrent.c b/lib/stub/setgrent.c
index 5e6e27e2..daa6d89d 100644
--- a/lib/stub/setgrent.c
+++ b/lib/stub/setgrent.c
@@ -19,6 +19,7 @@
  */
 
 #include <mes/lib.h>
+#include <errno.h>
 
 void
 setgrent (void)