diff --git a/lib/chibi/filesystem.sld b/lib/chibi/filesystem.sld
index bbaa20f6..f811470d 100644
--- a/lib/chibi/filesystem.sld
+++ b/lib/chibi/filesystem.sld
@@ -33,8 +33,7 @@
           file-lock        file-truncate
           file-is-readable? file-is-writable? file-is-executable?
           lock/shared lock/exclusive lock/non-blocking lock/unlock
-          is-a-tty?)
+          chmod is-a-tty?)
   (import (chibi) (chibi string))
   (include-shared "filesystem")
   (include "filesystem.scm"))
-
diff --git a/lib/chibi/filesystem.stub b/lib/chibi/filesystem.stub
index f5dc1843..22730cd7 100644
--- a/lib/chibi/filesystem.stub
+++ b/lib/chibi/filesystem.stub
@@ -212,6 +212,10 @@
 ;;> Locking operations.
 ;;/
 
+;;> Sets the file permissions as in chmod.
+
+(define-c int chmod (string int))
+
 ;;> Returns \scheme{#t} if the given port of file descriptor
 ;;> if backed by a TTY object, and \scheme{#f} otherwise.