diff --git a/compiler/bootstrapped-primitives.rkt b/compiler/bootstrapped-primitives.rkt
index eaf02a6..726e699 100644
--- a/compiler/bootstrapped-primitives.rkt
+++ b/compiler/bootstrapped-primitives.rkt
@@ -71,7 +71,7 @@
     ;; abandon the current continuation, initialize the control and environment, and then jump.
     call/cc-closure-entry
     (make-AssignImmediate 'val (make-EnvLexicalReference 0 #f))
-    (make-Perform (make-InstallClosureValues!))
+    (make-Perform (make-InstallClosureValues! 2))
     (make-Perform (make-RestoreControl! default-continuation-prompt-tag))
     (make-Perform (make-RestoreEnvironment!))
     (make-AssignImmediate 'proc (make-ControlStackLabel))
diff --git a/compiler/compiler.rkt b/compiler/compiler.rkt
index 3928793..df6c632 100644
--- a/compiler/compiler.rkt
+++ b/compiler/compiler.rkt
@@ -855,7 +855,8 @@
                                        (if (not (empty? (Lam-closure-map exp)))
                                            (append-instruction-sequences
                                             (make-Comment (format "installing closure for ~s" (Lam-name exp)))
-                                            (make-Perform (make-InstallClosureValues!)))
+                                            (make-Perform (make-InstallClosureValues!
+                                                           (length (Lam-closure-map exp)))))
                                            empty-instruction-sequence)]
          [lam-body-code : InstructionSequence
                         (compile (Lam-body exp)
diff --git a/compiler/il-structs.rkt b/compiler/il-structs.rkt
index e9b0537..f4d277e 100644
--- a/compiler/il-structs.rkt
+++ b/compiler/il-structs.rkt
@@ -387,7 +387,7 @@
 
 ;; Adjusts the environment by pushing the values in the
 ;; closure (held in the proc register) into itself.
-(define-struct: InstallClosureValues! ()
+(define-struct: InstallClosureValues! ([n : Natural])
   #:transparent)