diff --git a/coleslaw.asd b/coleslaw.asd
index fe13837..24d224d 100644
--- a/coleslaw.asd
+++ b/coleslaw.asd
@@ -13,7 +13,8 @@
                :inferior-shell
                :cl-fad
                :cl-ppcre
-               :closer-mop)
+               :closer-mop
+			   :cl-unicode)
   :serial t
   :components ((:file "packages")
                (:file "util")
diff --git a/src/content.lisp b/src/content.lisp
index a19be2d..87698c3 100644
--- a/src/content.lisp
+++ b/src/content.lisp
@@ -22,16 +22,24 @@
 
 ;; Slugs
 
-(defun slug-char-p (char)
+(defun slug-char-p (char &key (allowed-chars (list #\- #\~)))
   "Determine if CHAR is a valid slug (i.e. URL) character."
-  (or (char<= #\0 char #\9)
-      (char<= #\a char #\z)
-      (char<= #\A char #\Z)
-      (member char '(#\_ #\-))))
+  ; use the first char of the general unicode category as kind of
+  ; hyper general category
+  (let ((cat (aref (cl-unicode:general-category char) 0))
+		(allowed-cats (list #\L #\N))) ; allowed Unicode categories in URLs
+	(cond
+	  ((member cat allowed-cats)   t)
+	  ((member char allowed-chars) t)
+	  (t nil))))
+
+(defun unicode-space-p (char)
+  "Determine if CHAR is a kind of whitespace by unicode category means"
+  (char= (aref (cl-unicode:general-category char) 0) #\Z))
 
 (defun slugify (string)
   "Return a version of STRING suitable for use as a URL."
-  (remove-if-not #'slug-char-p (substitute #\- #\Space string)))
+  (remove-if-not #'slug-char-p (substitute-if #\- #'unicode-space-p string)))
 
 ;; Content Types