diff --git a/src/common/common.js b/src/common/common.js
new file mode 100644
index 0000000..28c233a
--- /dev/null
+++ b/src/common/common.js
@@ -0,0 +1,44 @@
+const defaultOptions = {
+  'list': true,
+  'thread': true,
+  'threadall': false,
+  'fixedtoolbar': false,
+  'redirect': false,
+  'history': false,
+  'loaddrafts': false,
+  'batchduplicate': false,
+  'escalatethreads': false,
+  'movethreads': false,
+  'increasecontrast': false,
+  'stickysidebarheaders': false,
+  'profileindicator': false,
+};
+
+const deprecatedOptions = [
+  'escalatethreads',
+  'movethreads',
+  'batchduplicate',
+];
+
+function isEmpty(obj) {
+  return Object.keys(obj).length === 0;
+}
+
+function cleanUpOptions(options) {
+  console.log('[cleanUpOptions] Previous options', options);
+  var ok = true;
+  for (const [opt, value] of Object.entries(defaultOptions)) {
+    if (!(opt in options)) {
+      ok = false;
+      options[opt] = value;
+    }
+  }
+
+  console.log('[cleanUpOptions] New options', options);
+
+  if (!ok) {
+    chrome.storage.sync.set(options);
+  }
+
+  return options;
+}