diff --git a/chrome/content/zotero/icon.js b/chrome/content/zotero/icon.js
index ccfcbee10..2f2c06d69 100644
--- a/chrome/content/zotero/icon.js
+++ b/chrome/content/zotero/icon.js
@@ -248,7 +248,14 @@ function getTooltipText(button) {
 				let src = 'chrome://zotero/locale/zotero.properties';
 				let localeService = Components.classes['@mozilla.org/intl/nslocaleservice;1']
 					.getService(Components.interfaces.nsILocaleService);
-				let appLocale = localeService.getApplicationLocale();
+				Components.utils.import("resource://gre/modules/Services.jsm");
+				if (Services.locale.getAppLocale) {
+					var appLocale = Services.locale.getAppLocale();
+				}
+				// Fx <=53
+				else {
+					var appLocale = Services.locale.getApplicationLocale();
+				}
 				let stringBundleService = Components.classes["@mozilla.org/intl/stringbundle;1"]
 					.getService(Components.interfaces.nsIStringBundleService);
 				let stringBundle = stringBundleService.createBundle(src, appLocale);
diff --git a/chrome/content/zotero/xpcom/zotero.js b/chrome/content/zotero/xpcom/zotero.js
index b00e86559..d9ddf2f1c 100644
--- a/chrome/content/zotero/xpcom/zotero.js
+++ b/chrome/content/zotero/xpcom/zotero.js
@@ -270,9 +270,13 @@ Components.utils.import("resource://gre/modules/Services.jsm");
 		var stringBundleService =
 			Components.classes["@mozilla.org/intl/stringbundle;1"]
 			.getService(Components.interfaces.nsIStringBundleService);
-		var localeService = Components.classes['@mozilla.org/intl/nslocaleservice;1'].
-							getService(Components.interfaces.nsILocaleService);
-		var appLocale = localeService.getApplicationLocale();
+		if (Services.locale.getAppLocale) {
+			var appLocale = Services.locale.getAppLocale();
+		}
+		// Fx <=53
+		else {
+			var appLocale = Services.locale.getApplicationLocale();
+		}
 		
 		_localizedStringBundle = stringBundleService.createBundle(
 			"chrome://zotero/locale/zotero.properties", appLocale);
@@ -1492,17 +1496,13 @@ Components.utils.import("resource://gre/modules/Services.jsm");
 			return this.collation;
 		}
 		
-		var localeService = Components.classes["@mozilla.org/intl/nslocaleservice;1"]
-				.getService(Components.interfaces.nsILocaleService);
-		var appLocale = localeService.getApplicationLocale();
-		
-		// Use nsICollation before Fx30
-		if (Zotero.platformMajorVersion < 30) {
-			var localeService = Components.classes["@mozilla.org/intl/nslocaleservice;1"]
-				.getService(Components.interfaces.nsILocaleService);
-			var collationFactory = Components.classes["@mozilla.org/intl/collation-factory;1"]
-				.getService(Components.interfaces.nsICollationFactory);
-			return this.collation = collationFactory.CreateCollation(appLocale);
+		Components.utils.import("resource://gre/modules/Services.jsm");
+		if (Services.locale.getAppLocale) {
+			var appLocale = Services.locale.getAppLocale();
+		}
+		// Fx <=53
+		else {
+			var appLocale = Services.locale.getApplicationLocale();
 		}
 		
 		try {
diff --git a/chrome/skin/default/zotero/timeline/timelineControls.js b/chrome/skin/default/zotero/timeline/timelineControls.js
index d0cd1f18b..80fd121ef 100644
--- a/chrome/skin/default/zotero/timeline/timelineControls.js
+++ b/chrome/skin/default/zotero/timeline/timelineControls.js
@@ -7,9 +7,15 @@ var lastJumpToYearValue;
  */
 function initLocaleBundle() {
 	var src = 'chrome://zotero/locale/timeline.properties';
-	var localeService = Components.classes['@mozilla.org/intl/nslocaleservice;1']
-		.getService(Components.interfaces.nsILocaleService);
-	var appLocale = localeService.getApplicationLocale();
+	
+	Components.utils.import("resource://gre/modules/Services.jsm");
+	if (Services.locale.getAppLocale) {
+		var appLocale = Services.locale.getAppLocale();
+	}
+	// Fx <=53
+	else {
+		var appLocale = Services.locale.getApplicationLocale();
+	}
 	
 	var stringBundleService = Components.classes["@mozilla.org/intl/stringbundle;1"]
 			.getService(Components.interfaces.nsIStringBundleService);