diff --git a/Makefile.am b/Makefile.am
index 5a4fa26..1efbaa0 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -48,6 +48,7 @@ MODULES =                                       \
   geesh/built-ins/false.scm                     \
   geesh/built-ins/read.scm                      \
   geesh/built-ins/readonly.scm                  \
+  geesh/built-ins/set.scm                       \
   geesh/built-ins/true.scm                      \
   geesh/built-ins/unset.scm                     \
   geesh/built-ins/utils.scm                     \
diff --git a/geesh/built-ins.scm b/geesh/built-ins.scm
index 249cf31..cf29b01 100644
--- a/geesh/built-ins.scm
+++ b/geesh/built-ins.scm
@@ -42,7 +42,7 @@
     ("export" . ,(@@ (geesh built-ins export) main))
     ("readonly" . ,(@@ (geesh built-ins readonly) main))
     ("return" . ,undefined)
-    ("set" . ,undefined)
+    ("set" . ,(@@ (geesh built-ins set) main))
     ("shift" . ,undefined)
     ("times" . ,undefined)
     ("trap" . ,undefined)
diff --git a/geesh/built-ins/set.scm b/geesh/built-ins/set.scm
new file mode 100644
index 0000000..2d721f5
--- /dev/null
+++ b/geesh/built-ins/set.scm
@@ -0,0 +1,33 @@
+;;; The Geesh Shell Interpreter
+;;; Copyright 2018 Timothy Sample <samplet@ngyro.com>
+;;;
+;;; This file is part of Geesh.
+;;;
+;;; Geesh 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 3 of the License, or
+;;; (at your option) any later version.
+;;;
+;;; Geesh 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 Geesh.  If not, see <http://www.gnu.org/licenses/>.
+
+(define-module (geesh built-ins set)
+  #:use-module (geesh environment)
+  #:use-module (ice-9 match))
+
+;;; Commentary:
+;;;
+;;; The 'set' utility.
+;;;
+;;; Code:
+
+
+(define (main env . args)
+  (match args
+    (("--" . args) (set-environment-arguments! env args))
+    (_ (throw 'not-implemented (string-join (cons "set" args))))))
diff --git a/geesh/environment.scm b/geesh/environment.scm
index 3ab50a9..637c3f6 100644
--- a/geesh/environment.scm
+++ b/geesh/environment.scm
@@ -38,6 +38,7 @@
             define-environment-function!
             delete-environment-functions!
             environment-arguments
+            set-environment-arguments!
             with-environment-arguments
             environment-break-prompt
             environment-continue-prompt))