diff --git a/resources/functionMap.php b/resources/functionMap.php
index 2b31468b37..e1dc331825 100644
--- a/resources/functionMap.php
+++ b/resources/functionMap.php
@@ -5957,11 +5957,11 @@
 'Locale::filterMatches' => ['bool|null', 'langtag'=>'string', 'locale'=>'string', 'canonicalize='=>'bool'],
 'Locale::getAllVariants' => ['array|null', 'locale'=>'string'],
 'Locale::getDefault' => ['non-empty-string'],
-'Locale::getDisplayLanguage' => ['non-empty-string', 'locale'=>'string', 'displayLocale='=>'string'],
-'Locale::getDisplayName' => ['non-empty-string', 'locale'=>'string', 'displayLocale='=>'string'],
-'Locale::getDisplayRegion' => ['non-empty-string', 'locale'=>'string', 'displayLocale='=>'string'],
-'Locale::getDisplayScript' => ['string', 'locale'=>'string', 'displayLocale='=>'string'],
-'Locale::getDisplayVariant' => ['string', 'locale'=>'string', 'displayLocale='=>'string'],
+'Locale::getDisplayLanguage' => ['non-empty-string|false', 'locale'=>'string', 'displayLocale='=>'string'],
+'Locale::getDisplayName' => ['non-empty-string|false', 'locale'=>'string', 'displayLocale='=>'string'],
+'Locale::getDisplayRegion' => ['string|false', 'locale'=>'string', 'displayLocale='=>'string'],
+'Locale::getDisplayScript' => ['string|false', 'locale'=>'string', 'displayLocale='=>'string'],
+'Locale::getDisplayVariant' => ['string|false', 'locale'=>'string', 'displayLocale='=>'string'],
 'Locale::getKeywords' => ['array|null', 'locale'=>'string'],
 'Locale::getPrimaryLanguage' => ['non-empty-string|null', 'locale'=>'string'],
 'Locale::getRegion' => ['string|null', 'locale'=>'string'],
@@ -5975,11 +5975,11 @@
 'locale_filter_matches' => ['bool|null', 'langtag'=>'string', 'locale'=>'string', 'canonicalize='=>'bool'],
 'locale_get_all_variants' => ['array|null', 'locale'=>'string'],
 'locale_get_default' => ['non-empty-string'],
-'locale_get_display_language' => ['non-empty-string', 'locale'=>'string', 'displayLocale='=>'string'],
-'locale_get_display_name' => ['non-empty-string', 'locale'=>'string', 'displayLocale='=>'string'],
-'locale_get_display_region' => ['non-empty-string', 'locale'=>'string', 'displayLocale='=>'string'],
-'locale_get_display_script' => ['string', 'locale'=>'string', 'displayLocale='=>'string'],
-'locale_get_display_variant' => ['string', 'locale'=>'string', 'displayLocale='=>'string'],
+'locale_get_display_language' => ['non-empty-string|false', 'locale'=>'string', 'displayLocale='=>'string'],
+'locale_get_display_name' => ['non-empty-string|false', 'locale'=>'string', 'displayLocale='=>'string'],
+'locale_get_display_region' => ['string|false', 'locale'=>'string', 'displayLocale='=>'string'],
+'locale_get_display_script' => ['string|false', 'locale'=>'string', 'displayLocale='=>'string'],
+'locale_get_display_variant' => ['string|false', 'locale'=>'string', 'displayLocale='=>'string'],
 'locale_get_keywords' => ['array|null', 'locale'=>'string'],
 'locale_get_primary_language' => ['non-empty-string|null', 'locale'=>'string'],
 'locale_get_region' => ['string|null', 'locale'=>'string'],