diff --git a/lib/tree-updater.rkt b/lib/tree-updater.rkt
index 879ff90..074c5a1 100644
--- a/lib/tree-updater.rkt
+++ b/lib/tree-updater.rkt
@@ -100,29 +100,19 @@
   (define (cardimage-class-updater c)
     (string-append c " bw-updated-cardtable-cardimage"))
 
-  ; precompute wikiurl regex for efficency
-  (define wikiurl-regex (pregexp (format "^https://(~a)\\.fandom\\.com(/wiki/.*)$" px-wikiname)))
-
   (define attributes-updater
     (compose1
      ; uncollapsing
      #;(curry attribute-maybe-update 'class
               (λ (class) (string-join (classlist-updater (string-split class " ")) " ")))
      (curry attribute-maybe-update 'class class-updater)
-
      ; change links to stay on the same wiki
-     (let
-       ; precompute wikiname replacement pattern
-       ([wiki-substitution (format "/~a\\1" wikiname)])
-       (curry attribute-maybe-update 'href
-              (λ (href)
-                ((compose1
-                  ; ok so these don't actually depend on each other.
-                  ; one will match or the other
-                  ; also we don't really need regex here.
-                  (λ (href) (regexp-replace #rx"^(/wiki/.*)$" href wiki-substitution))
-                  (λ (href) (regexp-replace wikiurl-regex href "/\\1\\2")))
-                 href))))
+     (curry attribute-maybe-update 'href
+            (λ (href)
+              ((compose1
+                (λ (href) (regexp-replace #rx"^(/wiki/.*)" href (format "/~a\\1" wikiname)))
+                (λ (href) (regexp-replace (pregexp (format "^https://(~a)\\.fandom\\.com(/wiki/.*)" px-wikiname)) href "/\\1\\2")))
+               href)))
      ; add noreferrer to a.image
      (curry u
             (λ (v) (and #;(eq? element-type 'a)
diff --git a/lib/xexpr-utils.rkt b/lib/xexpr-utils.rkt
index b1538d6..018d8c3 100644
--- a/lib/xexpr-utils.rkt
+++ b/lib/xexpr-utils.rkt
@@ -190,9 +190,7 @@
                 '(body "Hey" (& nbsp) (a (@ (href "/"))))))
 
 (define (has-class? name attributes)
-  ; splitting without specifying separator or splitting on #px"\\s+" makes
-  ; string-split use a faster whitespace-specialized implementation.
-  (and (member name (string-split (or (get-attribute 'class attributes) "") #px"\\s+")) #t))
+  (and (member name (string-split (or (get-attribute 'class attributes) "") " ")) #t))
 (module+ test
   (check-true (has-class? "red" '((class "yellow red blue"))))
   (check-false (has-class? "red" '((class "yellow blue"))))