diff --git a/sysdeps/posix/Makefile b/sysdeps/posix/Makefile
new file mode 100644
index 0000000000..b58aa6aadb
--- /dev/null
+++ b/sysdeps/posix/Makefile
@@ -0,0 +1,5 @@
+# These affect the generated bits/stdio_lim.h file.
+L_tmpnam  = 20
+TMP_MAX   = 238328
+L_ctermid = 9
+L_cuserid = 9