diff --git a/toolkit/mozapps/extensions/XPIProvider.jsm b/toolkit/mozapps/extensions/XPIProvider.jsm
index 324c303c51c..84ad6a2cf97 100644
--- a/toolkit/mozapps/extensions/XPIProvider.jsm
+++ b/toolkit/mozapps/extensions/XPIProvider.jsm
@@ -344,7 +344,7 @@ SafeInstallOperation.prototype = {
 function getLocale() {
   if (Prefs.getBoolPref(PREF_MATCH_OS_LOCALE, false))
     return Services.locale.getLocaleComponentForUserAgent();
-  let locale = Prefs.getComplexPref(PREF_SELECTED_LOCALE, Ci.nsIPrefLocalizedString);
+  let locale = Prefs.getComplexValue(PREF_SELECTED_LOCALE, Ci.nsIPrefLocalizedString);
   if (locale)
     return locale;
   return Prefs.getCharPref(PREF_SELECTED_LOCALE, "en-US");
@@ -1229,9 +1229,9 @@ var Prefs = {
    *         A value to return if the preference does not exist
    * @return the value of the preference or aDefaultValue if there is none
    */
-  getComplexPref: function(aName, aType, aDefaultValue) {
+  getComplexValue: function(aName, aType, aDefaultValue) {
     try {
-      return Services.prefs.getComplexPref(aName, aType).data;
+      return Services.prefs.getComplexValue(aName, aType).data;
     }
     catch (e) {
     }
diff --git a/toolkit/mozapps/extensions/nsBlocklistService.js b/toolkit/mozapps/extensions/nsBlocklistService.js
index 427977ad2a5..ec6d30e13ae 100644
--- a/toolkit/mozapps/extensions/nsBlocklistService.js
+++ b/toolkit/mozapps/extensions/nsBlocklistService.js
@@ -246,8 +246,8 @@ function getLocale() {
   try {
       // Get the default branch
       var defaultPrefs = gPref.getDefaultBranch(null);
-      return defaultPrefs.getComplexPref(PREF_GENERAL_USERAGENT_LOCALE,
-                                         Ci.nsIPrefLocalizedString).data;
+      return defaultPrefs.getComplexValue(PREF_GENERAL_USERAGENT_LOCALE,
+                                          Ci.nsIPrefLocalizedString).data;
   } catch (e) {}
 
   return gPref.getCharPref(PREF_GENERAL_USERAGENT_LOCALE);