diff --git a/Code/clostrum.lisp b/Code/clostrum.lisp
index 66a277a..af94706 100644
--- a/Code/clostrum.lisp
+++ b/Code/clostrum.lisp
@@ -57,7 +57,8 @@
 (define-accessor env:symbol-value (client environment variable-name))
 (defgeneric env:boundp (client env variable-name))
 (defgeneric env:makunbound (client env variable-name))
-(defgeneric env:make-variable (client environment variable-name value))
+(defgeneric env:make-variable (client environment variable-name
+                               &optional value))
 (defgeneric env:make-parameter (client environment variable-name value))
 (defgeneric env:make-constant (client environment variable-name value))
 (defgeneric env:make-symbol-macro (client environment variable-name expansion))
diff --git a/Code/default-methods.lisp b/Code/default-methods.lisp
index 5c91039..7e18d79 100644
--- a/Code/default-methods.lisp
+++ b/Code/default-methods.lisp
@@ -83,18 +83,20 @@
   (sys:variable-cell-makunbound
    client (sys:variable-cell client environment variable-name)))
 
-(defmethod env:make-variable (client environment variable-name new)
+(defmethod env:make-variable (client environment variable-name
+                              &optional (value nil valuep))
   (ecase (sys:variable-status client environment variable-name)
     ((nil)
-     (setf (sys:variable-cell-value
-            client (sys:variable-cell client environment variable-name))
-           new
-           (sys:variable-status client environment variable-name)
-           :special))
+     (when valuep
+       (setf (sys:variable-cell-value
+              client (sys:variable-cell client environment variable-name))
+             value))
+     (setf (sys:variable-status client environment variable-name) :special))
     ((:special)
-     (let ((cell (sys:variable-cell client environment variable-name)))
-       (unless (sys:variable-cell-boundp client cell)
-         (setf (sys:variable-cell-value client cell) new))))
+     (when valuep
+       (let ((cell (sys:variable-cell client environment variable-name)))
+         (unless (sys:variable-cell-boundp client cell)
+           (setf (sys:variable-cell-value client cell) value)))))
     ((:constant)
      (error 'env:attempt-to-define-special-variable-for-existing-constant
             :name variable-name))
diff --git a/Code/documentation.lisp b/Code/documentation.lisp
index 2ffe6dd..4d6ff4e 100644
--- a/Code/documentation.lisp
+++ b/Code/documentation.lisp
@@ -143,7 +143,7 @@ The nature of a setf expander is otherwise implementation-defined. One choice wo
   (function env:makunbound
     "As CL:MAKUNBOUND. Make VARIABLE-NAME have no global value in ENVIRONMENT. Returns VARIABLE-NAME.")
   (function env:make-variable
-    "Functional version of CL:DEFVAR. Proclaim VARIABLE-NAME special, and if it has no global value, set its global value to VALUE.")
+    "Functional version of CL:DEFVAR. Proclaim VARIABLE-NAME special, and if it has no global value and VALUE is provided, set its global value to VALUE.")
   (function env:make-parameter
     "Functional version of CL:DEFPARAMETER. Proclaim VARiABLE-NAME special, and set its global value to VALUE.")
   (function env:make-constant