diff --git a/src/common/extUtils.js b/src/common/extUtils.js
index 1777c87..e47a74c 100644
--- a/src/common/extUtils.js
+++ b/src/common/extUtils.js
@@ -1,11 +1,3 @@
-// This method is based on the fact that when building the extension for Firefox
-// the browser_specific_settings.gecko entry is included.
-export function isFirefox() {
-  var manifest = chrome.runtime.getManifest();
-  return manifest.browser_specific_settings !== undefined &&
-      manifest.browser_specific_settings.gecko !== undefined;
-}
-
 // Returns whether the extension is a release version.
 export function isReleaseVersion() {
   var manifest = chrome.runtime.getManifest();
diff --git a/src/common/optionsPrototype.json5 b/src/common/optionsPrototype.json5
index 38cfaca..824b754 100644
--- a/src/common/optionsPrototype.json5
+++ b/src/common/optionsPrototype.json5
@@ -75,11 +75,13 @@
     context: 'options',
     killSwitchType: 'option',
   },
+  // #!if ['chromium', 'chromium_mv3'].includes(browser_target)
   'ccdragndropfix': {
     defaultValue: false,
     context: 'options',
     killSwitchType: 'option',
   },
+  // #!endif
   'batchlock': {
     defaultValue: false,
     context: 'options',
diff --git a/src/common/specialOptions.json5 b/src/common/specialOptions.json5
index 55dde20..37b69fa 100644
--- a/src/common/specialOptions.json5
+++ b/src/common/specialOptions.json5
@@ -2,5 +2,4 @@
   'profileindicatoralt_months',
   'ccdarktheme_mode',
   'ccdarktheme_switch_enabled',
-  'ccdragndropfix',
 ]