diff --git a/src/common/common.js b/src/common/common.js
index 1a67bca..6bfdf02 100644
--- a/src/common/common.js
+++ b/src/common/common.js
@@ -18,12 +18,14 @@
   'ccdarktheme_mode': 'switch',
   'ccdarktheme_switch_enabled': true,
   'ccforcehidedrawer': false,
+  'ccdragndropfix': false,
 };
 
 const specialOptions = [
   'profileindicatoralt_months',
   'ccdarktheme_mode',
   'ccdarktheme_switch_enabled',
+  'ccdragndropfix',
 ];
 
 const deprecatedOptions = [
@@ -59,3 +61,11 @@
 
   return options;
 }
+
+// This method is based on the fact that when building the extension for Firefox
+// the browser_specific_settings.gecko entry is included.
+function isFirefox() {
+  var manifest = chrome.runtime.getManifest();
+  return manifest.browser_specific_settings !== undefined &&
+      manifest.browser_specific_settings.gecko !== undefined;
+}