diff --git a/lib/init-7.scm b/lib/init-7.scm
index 428565a8..9b7616fb 100644
--- a/lib/init-7.scm
+++ b/lib/init-7.scm
@@ -19,7 +19,7 @@
 (define (procedure? x) (if (closure? x) #t (opcode? x)))
 
 (define (length ls)
-  (if (list? ls) (length* ls) (error "not a list" ls)))
+  (if (list? ls) (length* ls) (error "length: not a list" ls)))
 
 (define (list . args) args)
 
@@ -646,7 +646,7 @@
            (_quote (rename 'syntax-quote)) (_apply (rename 'apply))
            (_append (rename 'append))      (_map (rename 'map))
            (_vector? (rename 'vector?))    (_list? (rename 'list?))
-           (_len (rename'len))             (_length (rename 'length))
+           (_len (rename'len))             (_length (rename 'length*))
            (_- (rename '-))   (_>= (rename '>=))   (_error (rename 'error))
            (_ls (rename 'ls)) (_res (rename 'res)) (_i (rename 'i))
            (_reverse (rename 'reverse))