diff --git a/members-base.scm b/members-base.scm
index 3e72612..dea3c93 100644
--- a/members-base.scm
+++ b/members-base.scm
@@ -38,6 +38,7 @@
   members-base-stats
   get-free-members-ids
   gen-member-id
+  members-base-update
   )
 
  (import scheme
@@ -187,4 +188,13 @@
 	  (vfids (list->vector fids)))
      (vector-ref vfids (pseudo-random-integer (vector-length vfids)))))
 
+ ;; Returns new members base with member records matching the
+ ;; predicate processed by proc.
+ (define (members-base-update mb pred? proc)
+   (map (lambda (mr)
+	  (if (pred? mr)
+	      (proc mr)
+	      mr))
+	mb))
+
  )