diff --git a/ext/bg/js/api.js b/ext/bg/js/api.js
index 8b4c3896..4b6729ad 100644
--- a/ext/bg/js/api.js
+++ b/ext/bg/js/api.js
@@ -18,15 +18,11 @@
 
 
 async function apiOptionsSet(options) {
-    // In Firefox, setting options from the options UI somehow carries references
-    // to the DOM across to the background page, causing the options object to
-    // become a "DeadObject" after the options page is closed. The workaround used
-    // here is to create a deep copy of the options object.
-    utilBackend().onOptionsUpdated(JSON.parse(JSON.stringify(options)));
+    utilBackend().onOptionsUpdated(utilIsolate(options));
 }
 
 async function apiOptionsGet() {
-    return utilBackend().options;
+    return utilIsolate(utilBackend().options);
 }
 
 async function apiTermsFind(text) {
diff --git a/ext/bg/js/util.js b/ext/bg/js/util.js
index 11ec23eb..a92fd0bc 100644
--- a/ext/bg/js/util.js
+++ b/ext/bg/js/util.js
@@ -22,6 +22,10 @@ function utilAsync(func) {
     };
 }
 
+function utilIsolate(data) {
+    return JSON.parse(JSON.stringify(data));
+}
+
 function utilBackend() {
     return chrome.extension.getBackgroundPage().yomichan_backend;
 }