diff --git a/test/challenge/discrete_value_range_test.clj b/test/challenge/discrete_value_range_test.clj
index 3e3badc..5d42c0c 100644
--- a/test/challenge/discrete_value_range_test.clj
+++ b/test/challenge/discrete_value_range_test.clj
@@ -3,8 +3,8 @@
    [clojure.test :refer [deftest testing is]]
    [challenge.discrete-value-range :as range]))
 
-(deftype IntInclusiveDiscreteValueRange
-         [^int start ^int end]
+(defrecord IntInclusiveDiscreteValueRange
+           [^int start ^int end]
   range/DiscreteValueRange
   (abuts [_this other]
     (or (= 1 (abs (- start (.end other))))
@@ -29,13 +29,10 @@
 
   Object
   (toString [_this]
-    (str start ".." end))
-  (equals [_this other]
-    (and (= start (.start other))
-         (= end (.end other)))))
+    (str start ".." end)))
 
 (defn int-range-inclusive [start end]
-  (assert (<= start end))
+  (assert (<= start end) (str "start : " start "; end: " end))
   (->IntInclusiveDiscreteValueRange start end))
 
 (defmethod range/->discrete-value-range :int-range-inclusive [_ start end]