diff --git a/src/build/libgnuregex/Jamfile b/src/build/libgnuregex/Jamfile
index cfcc8ef53f..ac52ac84ea 100644
--- a/src/build/libgnuregex/Jamfile
+++ b/src/build/libgnuregex/Jamfile
@@ -2,6 +2,7 @@ SubDir HAIKU_TOP src build libgnuregex ;
 
 BuildPlatformSharedLibrary libgnuregex_build.so :
 	regex.c
+	printchar.c
 	:
 	# no linked libraries here
 ;
diff --git a/src/build/libgnuregex/printchar.c b/src/build/libgnuregex/printchar.c
new file mode 100644
index 0000000000..2633b9b715
--- /dev/null
+++ b/src/build/libgnuregex/printchar.c
@@ -0,0 +1,43 @@
+/* Extended regular expression matching and search library,
+   version 0.12.
+   (Implements POSIX draft P10003.2/D11.2, except for
+   internationalization features.)
+
+   Copyright (C) 1993 Free Software Foundation, Inc.
+
+   This program 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 2, or (at your option)
+   any later version.
+
+   This program 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 this program; if not, write to the Free Software
+   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
+
+/* (this file was downloaded from
+ * https://raw.githubusercontent.com/ge-ne/bibtool/master/regex-0.12/test/printchar.c ,
+ * where no copyright header is included).
+ */
+#ifdef DEBUG
+
+void
+printchar (c)
+     char c;
+{
+  if (c < 040 || c >= 0177)
+    {
+      putchar ('\\');
+      putchar (((c >> 6) & 3) + '0');
+      putchar (((c >> 3) & 7) + '0');
+      putchar ((c & 7) + '0');
+    }
+  else
+    putchar (c);
+}
+
+#endif