diff --git a/tests/test_loop.hy b/tests/test_loop.hy
index 43ce3cf3..363eacdd 100644
--- a/tests/test_loop.hy
+++ b/tests/test_loop.hy
@@ -1,11 +1,21 @@
 (require
   hyrule [loop])
 (import
+  math
   sys
-  hyrule [inc dec]
+  hyrule [inc dec recur]
   pytest)
 
 
+(defn test-factorial []
+  (assert (=
+    (loop [[i 5] [acc 1]]
+      (if (= i 0)
+       acc
+       (recur (dec i) (* acc i))))
+    (math.factorial 5))))
+
+
 (defn test-tco-sum []
 
   ; This plain old tail-recursive function should exceed Python's