diff --git a/src/files/html.ts b/src/files/html.ts
index eb2ede9..6205f5e 100644
--- a/src/files/html.ts
+++ b/src/files/html.ts
@@ -14,7 +14,8 @@ export type IFileHtmlOptions = IExtensionOptions<{
 
 const DEFAULTS = {
   commons: {
-    style: ['gatsby-global-css']
+    style: ['gatsby-global-css'],
+    script: ['gatsby-chunk-mapping']
   }
 }
 
diff --git a/src/tasks/purgecss/lib/purger.ts b/src/tasks/purgecss/lib/purger.ts
index 5f5aa1f..1bd0310 100644
--- a/src/tasks/purgecss/lib/purger.ts
+++ b/src/tasks/purgecss/lib/purger.ts
@@ -83,7 +83,7 @@ export class Purger {
       return cache.rejected
     }
 
-    const opts = this.purgeOptions
+    const opts = { ...this.purgeOptions }
     opts.content = []
     opts.css = []
     try {