diff --git a/wp-includes/js/media-models.js b/wp-includes/js/media-models.js
index 8da4cca52c..ba8854ac5a 100644
--- a/wp-includes/js/media-models.js
+++ b/wp-includes/js/media-models.js
@@ -39,7 +39,7 @@ window.wp = window.wp || {};
 	_.extend( media, { model: {}, view: {}, controller: {} });
 
 	// Link any localized strings.
-	l10n = media.model.l10n = _.isUndefined( _wpMediaModelsL10n ) ? {} : _wpMediaModelsL10n;
+	l10n = media.model.l10n = typeof _wpMediaModelsL10n === 'undefined' ? {} : _wpMediaModelsL10n;
 
 	/**
 	 * ========================================================================
diff --git a/wp-includes/js/media-views.js b/wp-includes/js/media-views.js
index 4a60fad850..4a9e6e413a 100644
--- a/wp-includes/js/media-views.js
+++ b/wp-includes/js/media-views.js
@@ -6,7 +6,7 @@
 		l10n;
 
 	// Link any localized strings.
-	l10n = media.view.l10n = _.isUndefined( _wpMediaViewsL10n ) ? {} : _wpMediaViewsL10n;
+	l10n = media.view.l10n = typeof _wpMediaViewsL10n === 'undefined' ? {} : _wpMediaViewsL10n;
 
 	// Link any settings.
 	media.view.settings = l10n.settings || {};