diff --git a/simulator.rkt b/simulator.rkt
index 539638f..43f4537 100644
--- a/simulator.rkt
+++ b/simulator.rkt
@@ -158,7 +158,15 @@
                      (make-toplevel (map lookup-primitive 
                                          (ExtendEnvironment/Prefix!-names op))))]
           [(InstallClosureValues!? op)
-           (error 'step-perform)])))
+           (let: ([a-proc : SlotValue (machine-proc m)])
+                 (cond
+                   [(closure? a-proc)
+                    (env-push-many m
+                                   (closure-vals a-proc))]
+                   [else
+                    (error 'step-perform "Procedure register doesn't hold a procedure: ~s"
+                           a-proc)]))])))
+           
 
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 
@@ -258,6 +266,13 @@
     [(struct machine (val proc env control pc text))
      (make-machine val proc (cons v env) control pc text)]))
 
+(: env-push-many (machine (Listof SlotValue) -> machine))
+(define (env-push-many m vs)
+  (match m
+    [(struct machine (val proc env control pc text))
+     (make-machine val proc (append vs env) control pc text)]))
+
+
 (: env-ref (machine Natural -> Any))
 (define (env-ref m i)  
   (match m
diff --git a/test-simulator.rkt b/test-simulator.rkt
index 2358fc7..fc17eac 100644
--- a/test-simulator.rkt
+++ b/test-simulator.rkt
@@ -270,3 +270,18 @@
                         ,(make-PerformStatement (make-CheckToplevelBound! 0 0 'some-variable))))])
   (void (run m)))
 
+
+
+;; install-closure-values
+(let ([m  
+       (make-machine (make-undefined) (make-closure 'procedure-entry
+                                                    (list 1 2 3))
+                     (list true false) ;; existing environment holds true, false
+                     '() 
+                     0 
+                     (list->vector `(,(make-PerformStatement (make-InstallClosureValues!))
+                                     procedure-entry
+                                     )))])
+  (test (machine-env (run m))
+        ;; Check that the environment has installed the expected closure values.
+        (list 1 2 3 true false)))
\ No newline at end of file