diff --git a/src/mw_engine/core.clj b/src/mw_engine/core.clj
index 2bdeb1b..ab48826 100644
--- a/src/mw_engine/core.clj
+++ b/src/mw_engine/core.clj
@@ -2,8 +2,7 @@
 
 (ns mw-engine.core
   (:require [mw-engine.world :as world]
-        mw-engine.natural-rules
-        mw-engine.utils))
+            mw-engine.utils))
 
 ;; Every rule is a function of two arguments, a cell and a world. If the rule
 ;; fires, it returns a new cell, which should have the same values for :x and