diff --git a/simulator.rkt b/simulator.rkt
index b4bec13..126a95b 100644
--- a/simulator.rkt
+++ b/simulator.rkt
@@ -41,7 +41,7 @@
            [(TestAndBranchStatement? i)
             (error 'step)]
            [(PopEnvironment? i)
-            (error 'step)]
+            (step-pop-environment m i)]
            [(PushEnvironment? i)
             (step-push-environment m i)]
            [(PushControlFrame? i)
@@ -89,8 +89,16 @@
        (loop (env-push m (void))
              (sub1 n))])))
 
+(: step-pop-environment (machine PopEnvironment -> machine))
+(define (step-pop-environment machine stmt)
+  (env-pop machine
+           (PopEnvironment-n stmt)
+           (PopEnvironment-skip stmt)))
 
-;;;;;;;;;
+
+
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 
 
 (: evaluate-oparg (machine OpArg -> Any))
diff --git a/test-simulator.rkt b/test-simulator.rkt
index 82bdcdc..db48d7f 100644
--- a/test-simulator.rkt
+++ b/test-simulator.rkt
@@ -79,3 +79,42 @@
                          ,(make-AssignImmediateStatement (make-EnvLexicalReference 0) (make-Const 42))))]
        [m (run m)])
   (test (machine-env m) `(42 ,(void))))
+
+
+;; PushEnv
+(let ([m (new-machine `(,(make-PushEnvironment 20)))])
+  (test (machine-env (run m)) (build-list 20 (lambda (i) (void)))))
+
+
+;; PopEnv
+(let ([m (new-machine `(,(make-PushEnvironment 20)
+                        ,(make-PopEnvironment 20 0)))])
+  (test (machine-env (run m)) '()))
+
+(let* ([m (new-machine `(,(make-PushEnvironment 3)
+                        ,(make-AssignImmediateStatement (make-EnvLexicalReference 0) (make-Const "hewie"))
+                        ,(make-AssignImmediateStatement (make-EnvLexicalReference 1) (make-Const "dewey"))
+                        ,(make-AssignImmediateStatement (make-EnvLexicalReference 2) (make-Const "louie"))
+                        ,(make-PopEnvironment 1 0)))])
+  (test (machine-env (run m)) '("dewey" "louie")))
+
+(let* ([m (new-machine `(,(make-PushEnvironment 3)
+                        ,(make-AssignImmediateStatement (make-EnvLexicalReference 0) (make-Const "hewie"))
+                        ,(make-AssignImmediateStatement (make-EnvLexicalReference 1) (make-Const "dewey"))
+                        ,(make-AssignImmediateStatement (make-EnvLexicalReference 2) (make-Const "louie"))
+                        ,(make-PopEnvironment 1 1)))])
+  (test (machine-env (run m)) '("hewie" "louie")))
+
+(let* ([m (new-machine `(,(make-PushEnvironment 3)
+                        ,(make-AssignImmediateStatement (make-EnvLexicalReference 0) (make-Const "hewie"))
+                        ,(make-AssignImmediateStatement (make-EnvLexicalReference 1) (make-Const "dewey"))
+                        ,(make-AssignImmediateStatement (make-EnvLexicalReference 2) (make-Const "louie"))
+                        ,(make-PopEnvironment 1 2)))])
+  (test (machine-env (run m)) '("hewie" "dewey")))
+
+(let* ([m (new-machine `(,(make-PushEnvironment 3)
+                        ,(make-AssignImmediateStatement (make-EnvLexicalReference 0) (make-Const "hewie"))
+                        ,(make-AssignImmediateStatement (make-EnvLexicalReference 1) (make-Const "dewey"))
+                        ,(make-AssignImmediateStatement (make-EnvLexicalReference 2) (make-Const "louie"))
+                        ,(make-PopEnvironment 2 1)))])
+  (test (machine-env (run m)) '("hewie")))