diff --git a/test/com/rpl/specter/core_test.cljc b/test/com/rpl/specter/core_test.cljc
index e8b416c..8323b4f 100644
--- a/test/com/rpl/specter/core_test.cljc
+++ b/test/com/rpl/specter/core_test.cljc
@@ -1440,10 +1440,14 @@
   (is (= "abq" (setval s/LAST "q" "abc")))
   )
 
+(defn whitespace? [char]
+  (re-matches #"\s" (str char)))
+
 (deftest string-transform-test
   (is (= "123" (transform s/ALL identity "123")))
-  (is (= "123" (setval [s/ALL #(Character/isWhitespace %)] s/NONE "1 2 3")))
-  (is (= "123" (transform [(s/filterer #(Character/isWhitespace %))] s/NONE "1 2 3"))))
+  (is (= "123" (transform [s/ALL whitespace?] s/NONE "1 2 3")))
+  #?(:clj (is (= "123" (setval [s/ALL #(Character/isWhitespace %)] s/NONE "1 2 3"))))
+  #?(:clj (is (= "123" (transform [(s/filterer #(Character/isWhitespace %))] s/NONE "1 2 3")))))
 
 (deftest regex-navigation-test
   ;; also test regexes as implicit navs