diff --git a/simulator-structs.rkt b/simulator-structs.rkt
index b66bf15..2352df6 100644
--- a/simulator-structs.rkt
+++ b/simulator-structs.rkt
@@ -175,6 +175,11 @@
 
 
 
+(define-struct: ToplevelReference ([toplevel : toplevel]
+                                   [pos : Natural])
+  #:transparent)
+                
+
 ;; undefined value
 (define-struct: undefined ()
   #:transparent)
@@ -185,7 +190,3 @@
 (define-predicate frame? frame)
 
 
-(define-struct: ToplevelReference ([toplevel : toplevel]
-                                   [pos : Natural])
-  #:transparent)
-                
\ No newline at end of file
diff --git a/test-simulator.rkt b/test-simulator.rkt
index 57eee5a..452a28d 100644
--- a/test-simulator.rkt
+++ b/test-simulator.rkt
@@ -334,6 +334,7 @@
                      0 
                      (list->vector `(,(make-PerformStatement (make-InstallClosureValues!))
                                      procedure-entry))
+                     (make-hash)
                      0
                      (make-hash))])
   (test (machine-env (run! m))
@@ -350,6 +351,7 @@
                      '() 
                      0 
                      (list->vector `(,(make-AssignPrimOpStatement 'val (make-GetCompiledProcedureEntry))))
+                     (make-hash)
                      0
                      (make-hash))])
   (test (machine-val (run! m))