diff --git a/lib/core/constants.js b/lib/core/constants.js
index 71918e37..c5b9fd2b 100644
--- a/lib/core/constants.js
+++ b/lib/core/constants.js
@@ -27,7 +27,10 @@ const definitions = [
 
 const constants = {
   helpUrlBase: 'https://dequeuniversity.com/rules/',
+  // Size of a grid square in pixels
   gridSize: 200,
+  // At a certain point, looping over an array of elements and using .match on them
+  // is slower than just running querySelectorAll again.
   selectorSimilarFilterLimit: 700,
   results: [],
   resultGroups: [],
@@ -44,7 +47,15 @@ const constants = {
     timeout: 10000
   }),
   allOrigins: '<unsafe_all_origins>',
-  sameOrigin: '<same_origin>'
+  sameOrigin: '<same_origin>',
+  serializableErrorProps: Object.freeze([
+    'message',
+    'stack',
+    'name',
+    'code',
+    'ruleId',
+    'method'
+  ])
 };
 
 definitions.forEach(definition => {