diff --git a/build-aux/configure-lib.sh b/build-aux/configure-lib.sh
index 575e5212..c862fdeb 100644
--- a/build-aux/configure-lib.sh
+++ b/build-aux/configure-lib.sh
@@ -272,6 +272,8 @@ lib/stub/freadahead.c
 lib/stub/frexp.c
 lib/stub/fscanf.c
 lib/stub/getlogin.c
+lib/stub/getpgid.c
+lib/stub/getpgrp.c
 lib/stub/getpwnam.c
 lib/stub/getpwuid.c
 lib/stub/gmtime.c
diff --git a/include/unistd.h b/include/unistd.h
index 52820b15..86353729 100644
--- a/include/unistd.h
+++ b/include/unistd.h
@@ -74,8 +74,10 @@ int setgid (gid_t newgid);
 int setuid (uid_t newuid);
 uid_t geteuid (void);
 gid_t getegid (void);
+pid_t getpgrp (void);
 pid_t getpid (void);
 pid_t getppid (void);
+int getpgid (pid_t pid);
 int isatty (int fd);
 int link (char const *old_name, char const *new_name);
 off_t lseek (int fd, off_t offset, int whence);
@@ -90,7 +92,6 @@ void *sbrk (intptr_t delta);
 int symlink (char const *old_name, char const *new_name);
 int unlink (char const *file_name);
 ssize_t write (int filedes, void const *buffer, size_t size);
-pid_t getpid (void);
 
 #endif // ! SYSTEM_LIBC
 
diff --git a/lib/stub/getpgid.c b/lib/stub/getpgid.c
new file mode 100644
index 00000000..f82d3c5e
--- /dev/null
+++ b/lib/stub/getpgid.c
@@ -0,0 +1,33 @@
+/* -*-comment-start: "//";comment-end:""-*-
+ * GNU Mes --- Maxwell Equations of Software
+ * Copyright © 2019 Jan (janneke) Nieuwenhuizen <janneke@gnu.org>
+ *
+ * This file is part of GNU Mes.
+ *
+ * GNU Mes is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or (at
+ * your option) any later version.
+ *
+ * GNU Mes is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with GNU Mes.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <mes/lib.h>
+#include <unistd.h>
+
+int
+getpgid (pid_t pid)
+{
+  static int stub = 0;
+  if (__mes_debug () && !stub)
+    eputs ("getpgid stub\n");
+  stub = 1;
+  errno = 0;
+  return 0;
+}
diff --git a/lib/stub/getpgrp.c b/lib/stub/getpgrp.c
new file mode 100644
index 00000000..7b7510b1
--- /dev/null
+++ b/lib/stub/getpgrp.c
@@ -0,0 +1,33 @@
+/* -*-comment-start: "//";comment-end:""-*-
+ * GNU Mes --- Maxwell Equations of Software
+ * Copyright © 2019 Jan (janneke) Nieuwenhuizen <janneke@gnu.org>
+ *
+ * This file is part of GNU Mes.
+ *
+ * GNU Mes is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or (at
+ * your option) any later version.
+ *
+ * GNU Mes is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with GNU Mes.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <mes/lib.h>
+#include <unistd.h>
+
+pid_t
+getpgrp (void)
+{
+  static int stub = 0;
+  if (__mes_debug () && !stub)
+    eputs ("getpgrp stub\n");
+  stub = 1;
+  errno = 0;
+  return 0;
+}