Index: libcfa/prelude/extras.c
===================================================================
--- libcfa/prelude/extras.c	(revision 2fa0237f52bd8db42015c83dee0d38191a902db4)
+++ libcfa/prelude/extras.c	(revision 5cfb8b12c10a9e8aaf77d4435350d6b39af04561)
@@ -3,4 +3,5 @@
 #include <uchar.h>					// char16_t, char32_t
 #include <wchar.h>					// wchar_t
-#include <stdlib.h>					// malloc, free, exit, atexit, abort
+#include <stdlib.h>					// malloc, free, getenv, exit, atexit, abort, printf
 #include <stdio.h>					// printf
+#include <string.h>					// strlen, strcmp, strncmp
Index: libcfa/prelude/extras.regx2
===================================================================
--- libcfa/prelude/extras.regx2	(revision 2fa0237f52bd8db42015c83dee0d38191a902db4)
+++ libcfa/prelude/extras.regx2	(revision 5cfb8b12c10a9e8aaf77d4435350d6b39af04561)
@@ -1,6 +1,10 @@
 extern void \*malloc[^;]*;
 extern void free[^;]*;
+extern char \*getenv[^;]*;
 extern void exit[^;]*;
 extern int atexit[^;]*;
 extern void abort[^;]*;
 extern int printf[^;]*;
+int strcmp[^;]*;
+int strncmp[^;]*;
+size_t strlen[^;]*;