diff --git a/compiler+runtime/src/jank/clojure/core.jank b/compiler+runtime/src/jank/clojure/core.jank
index e2ed9d5b5..59366c3fe 100644
--- a/compiler+runtime/src/jank/clojure/core.jank
+++ b/compiler+runtime/src/jank/clojure/core.jank
@@ -32,10 +32,29 @@
 (def ex-info
   "Create an instance of ExceptionInfo, a RuntimeException subclass
    that carries a map of additional data."
-  ; TODO: Arity 3
-  (fn* ex-info [msg map]
-    {:error msg
-     :data map}))
+  (fn* ex-info
+    ([msg map]
+     {:error msg
+      :data map})
+    ([msg map cause]
+     {:error msg
+      :data map
+      :cause cause})))
+
+(def ex-message
+  "Returns the message attached to ex if ex is a Throwable.
+  Otherwise returns nil."
+  :error)
+
+(def ex-data
+  "Returns exception data (a map) if ex is an IExceptionInfo.
+   Otherwise returns nil."
+  :data)
+
+(def ex-cause
+  "Returns the cause of ex if ex is a Throwable.
+  Otherwise returns nil."
+  :cause)
 
 ; Relations.
 ;; Miscellaneous.
@@ -5698,30 +5717,6 @@
   ;;           (drop-while #(= class-name (.getClassName ^StackTraceElement %1)) tr))))))
   (throw "TODO: port"))
 
-(defn ex-data
-  "Returns exception data (a map) if ex is an IExceptionInfo.
-   Otherwise returns nil."
-  [ex]
-  ;; (when (instance? IExceptionInfo ex)
-  ;;   (.getData ^IExceptionInfo ex))
-  (throw "TODO: port"))
-
-(defn ex-message
-  "Returns the message attached to ex if ex is a Throwable.
-  Otherwise returns nil."
-  [ex]
-  ;; (when (instance? Throwable ex)
-  ;;   (.getMessage Throwable ex))
-  (throw "TODO: port"))
-
-(defn ex-cause
-  "Returns the cause of ex if ex is a Throwable.
-  Otherwise returns nil."
-  [ex]
-  ;; (when (instance? Throwable ex)
-  ;;   (.getCause ^Throwable ex))
-  (throw "TODO: port"))
-
 (defn test
   "test [v] finds fn at key :test in var metadata and calls it,
   presuming failure will throw exception"