diff --git a/lib/chibi/strings.scm b/lib/chibi/strings.scm
index 96fc44f7..8adc6ba6 100644
--- a/lib/chibi/strings.scm
+++ b/lib/chibi/strings.scm
@@ -5,10 +5,10 @@
 (define (string-null? str)
   (equal? str ""))
 
-;; TODO: support character sets
 (define (make-char-predicate x)
   (cond ((procedure? x) x)
         ((char? x) (lambda (ch) (eq? ch x)))
+	((char-set? x) (lambda (ch) (char-set-contains? x ch)))
         (else (error "invalid character predicate" x))))
 
 (define (complement pred) (lambda (x) (not (pred x))))
diff --git a/lib/chibi/strings.sld b/lib/chibi/strings.sld
index 890fc9fb..a1c13733 100644
--- a/lib/chibi/strings.sld
+++ b/lib/chibi/strings.sld
@@ -11,5 +11,5 @@
    string-find string-find-right string-skip string-skip-right
    string-fold string-fold-right string-map string-for-each
    string-contains make-string-searcher)
-  (import (scheme) (chibi ast))
+  (import (scheme) (chibi ast) (chibi char-set base))
   (include "strings.scm"))