diff --git a/src/objects/intl-objects.cc b/src/objects/intl-objects.cc
index e32be5d155..abeeb1d24c 100644
--- a/src/objects/intl-objects.cc
+++ b/src/objects/intl-objects.cc
@@ -397,11 +397,8 @@ std::string Intl::GetNumberingSystem(const icu::Locale& icu_locale) {
   UErrorCode status = U_ZERO_ERROR;
   std::unique_ptr<icu::NumberingSystem> numbering_system(
       icu::NumberingSystem::createInstance(icu_locale, status));
-  std::string value;
-  if (U_SUCCESS(status)) {
-    value = numbering_system->getName();
-  }
-  return value;
+  if (U_SUCCESS(status)) return numbering_system->getName();
+  return "latn";
 }
 
 icu::Locale Intl::CreateICULocale(const std::string& bcp47_locale) {
diff --git a/src/objects/js-number-format.cc b/src/objects/js-number-format.cc
index 2562c2ceef..47d5b71e8d 100644
--- a/src/objects/js-number-format.cc
+++ b/src/objects/js-number-format.cc
@@ -90,9 +90,8 @@ Handle<JSObject> JSNumberFormat::ResolvedOptions(
   Handle<String> locale =
       Handle<String>(number_format_holder->locale(), isolate);
 
-  UErrorCode error = U_ZERO_ERROR;
-  icu::Locale icu_locale = number_format->getLocale(ULOC_VALID_LOCALE, error);
-  DCHECK(U_SUCCESS(error));
+  std::unique_ptr<char[]> locale_str = locale->ToCString();
+  icu::Locale icu_locale = Intl::CreateICULocale(locale_str.get());
 
   std::string numbering_system = Intl::GetNumberingSystem(icu_locale);
 
diff --git a/test/intl/regress-8525.js b/test/intl/regress-8525.js
new file mode 100644
index 0000000000..4d925d73c3
--- /dev/null
+++ b/test/intl/regress-8525.js
@@ -0,0 +1,27 @@
+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// test the numberingSystem is set correctly via -u-nu-
+let dtf = new Intl.DateTimeFormat(["en-u-ba-rfoo-nu-arab-fo-obar"]);
+assertEquals("arab", dtf.resolvedOptions().numberingSystem);
+assertEquals("en-u-nu-arab", dtf.resolvedOptions().locale);
+
+let nf = new Intl.NumberFormat(["en-u-ba-rfoo-nu-arab-fo-obar"]);
+assertEquals("arab", nf.resolvedOptions().numberingSystem);
+assertEquals("١٢٣", nf.format(123));
+assertEquals("en-u-nu-arab", nf.resolvedOptions().locale);
+
+dtf = new Intl.DateTimeFormat(["en-u-ba-rfoo-nu-thai-fo-obar"]);
+assertEquals("thai", dtf.resolvedOptions().numberingSystem);
+assertEquals("en-u-nu-thai", dtf.resolvedOptions().locale);
+
+nf = new Intl.NumberFormat(["en-u-ba-rfoo-nu-thai-fo-obar"]);
+assertEquals("thai", nf.resolvedOptions().numberingSystem);
+assertEquals("๑๒๓", nf.format(123));
+assertEquals("en-u-nu-thai", nf.resolvedOptions().locale);
+
+nf = new Intl.NumberFormat(["ar-EG-u-nu-latn"]);
+assertEquals("latn", nf.resolvedOptions().numberingSystem);
+assertEquals("123", nf.format(123));
+assertEquals("ar-EG-u-nu-latn", nf.resolvedOptions().locale);