diff --git a/src/ikarus.boot b/src/ikarus.boot
index 0cf3bc4..88d6473 100644
Binary files a/src/ikarus.boot and b/src/ikarus.boot differ
diff --git a/src/ikarus.syntax.ss b/src/ikarus.syntax.ss
index d87c451..c5072b4 100644
--- a/src/ikarus.syntax.ss
+++ b/src/ikarus.syntax.ss
@@ -2272,7 +2272,7 @@
                macro*))))
   (define (library-expander x)
     (let-values ([(name imp* inv* vis* invoke-code macro* export-subst export-env)
-                    (core-library-expander x)])
+                  (core-library-expander x)])
       (let ([id (gensym)]
             [name name]
             [ver '()]  ;;; FIXME
@@ -2295,7 +2295,8 @@
   (define build-export
     (lambda (x)
       ;;; exports use the same gensym
-      `(#%$set-symbol-value! ',x ,x)))
+      `(begin
+         (#%$set-symbol-value! ',x ,x))))
   (define (make-export-subst int* ext* rib)
     (map
       (lambda (int ext)
diff --git a/src/makefile.ss b/src/makefile.ss
index 2dd58f5..792573c 100755
--- a/src/makefile.ss
+++ b/src/makefile.ss
@@ -696,6 +696,7 @@
     [$symbol-string             $symbols]
     [$symbol-plist              $symbols]
     [$set-symbol-value!         $symbols]
+    [$set-symbol-proc!          $symbols]
     [$set-symbol-string!        $symbols]
     [$set-symbol-unique-string! $symbols]
     [$set-symbol-plist!         $symbols]
diff --git a/src/pass-specify-rep-primops.ss b/src/pass-specify-rep-primops.ss
index 736dc35..5b070c1 100644
--- a/src/pass-specify-rep-primops.ss
+++ b/src/pass-specify-rep-primops.ss
@@ -452,10 +452,6 @@
      (prm 'mset x (K (- disp-symbol-record-value symbol-ptag))   (K unbound))
      (prm 'mset x (K (- disp-symbol-record-proc symbol-ptag))    (K unbound))
      (prm 'mset x (K (- disp-symbol-record-plist symbol-ptag))   (K nil))
-     ;(prm 'mset x (K (- disp-symbol-system-value symbol-tag)) (K unbound))
-     ;(prm 'mset x (K (- disp-symbol-function symbol-ptag)) (K 0))
-     ;(prm 'mset x (K (- disp-symbol-error-function symbol-ptag)) (K 0)) 
-     ;(prm 'mset x (K (- disp-symbol-unused symbol-tag)) (K 0))
      x)]
   [(P str) (K #t)]
   [(E str) (nop)])
@@ -491,6 +487,11 @@
      (prm 'mset x (K (- disp-symbol-record-value symbol-ptag)) (T v))
      (dirty-vector-set x))])
 
+(define-primop $set-symbol-proc! unsafe
+  [(E x v)
+   (with-tmp ([x (T x)])
+     (prm 'mset x (K (- disp-symbol-record-proc symbol-ptag)) (T v))
+     (dirty-vector-set x))])
 
 (define-primop top-level-value safe
   [(V x)