diff --git a/lib/mixins/property-effects.js b/lib/mixins/property-effects.js
index c60a0341b0..c6164ffc38 100644
--- a/lib/mixins/property-effects.js
+++ b/lib/mixins/property-effects.js
@@ -82,7 +82,8 @@ let DataEffect; //eslint-disable-line no-unused-vars
  *
  * @param {Object} model Prototype or instance
  * @param {string} type Property effect type
- * @param {boolean=} cloneArrays Clone any arrays mapped in the map
+ * @param {boolean=} cloneArrays Clone any arrays assigned to the map when
+ *   extending a superclass map onto this subclass
  * @return {Object} The own-property map of effects for the given type
  * @private
  */
@@ -2356,7 +2357,11 @@ export const PropertyEffects = dedupingMixin(superClass => {
         throw new Error("Malformed computed expression '" + expression + "'");
       }
       const info = createMethodEffect(this, sig, TYPES.COMPUTE, runComputedEffect, property, dynamicFn);
-      ensureOwnEffectMap(this, COMPUTE_INFO)[property] = info;
+      if (orderedComputed) {
+        // Effects are normally stored as map of dependency->effect, but for
+        // ordered computation, we also need tree of computedProp->dependencies 
+        ensureOwnEffectMap(this, COMPUTE_INFO)[property] = info;
+      }
     }
 
     /**