Defines error_t

diff --git a/src/ccze.h b/src/ccze.h
index 6f73999..c51618d 100644
--- a/src/ccze.h
+++ b/src/ccze.h
@@ -22,6 +22,8 @@
 #ifndef _CCZE_H
 #define _CCZE_H 1

+#include "error_t.h"
+
 #ifdef HAVE_SYSTEM_H
 # include "system.h"
 #endif
diff --git a/src/error_t.h b/src/error_t.h
new file mode 100644
index 0000000..b6c312b
--- /dev/null
+++ b/src/error_t.h
@@ -0,0 +1,20 @@
+/* Define error_t.
+   Copyright (C) 1991-2020 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+   The GNU C Library 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
+   Lesser General Public License for more details.
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+#ifndef __error_t_defined
+# define __error_t_defined 1
+
+typedef int error_t;
+
+#endif