diff --git a/scheme/ikarus.numerics.ss b/scheme/ikarus.numerics.ss
index 2915068..36d3753 100644
--- a/scheme/ikarus.numerics.ss
+++ b/scheme/ikarus.numerics.ss
@@ -1287,10 +1287,10 @@
               [else ($make-ratnum d n)]))]
          [(compnum? x) (binary/ 1 x)]
          [else (die '/ "not a number" x)])]
-      [(x y z . rest)
-       (let f ([a (binary/ x y)] [b z] [ls rest])
+      [(x y z . ls)
+       (let f ([a (binary/ x y)] [b z] [ls ls])
          (cond
-           [(null? rest) (binary/ a b)]
+           [(null? ls) (binary/ a b)]
            [else (f (binary/ a b) (car ls) (cdr ls))]))]))
 
 
diff --git a/scheme/makefile.ss b/scheme/makefile.ss
index 0bd49c0..9265f26 100755
--- a/scheme/makefile.ss
+++ b/scheme/makefile.ss
@@ -25,7 +25,7 @@
                 current-primitive-locations
                 compile-core-expr-to-port))
 (import (ikarus.compiler)) ; just for fun
-(optimize-level 2)
+(optimize-level 1)
 
 (pretty-width 160)
 ((pretty-format 'fix) ((pretty-format 'letrec)))