diff --git a/src/lib/moment/prototype.js b/src/lib/moment/prototype.js
index d472b1571d..c45630cb71 100644
--- a/src/lib/moment/prototype.js
+++ b/src/lib/moment/prototype.js
@@ -86,8 +86,9 @@ import {
     getSetWeekYear,
     getSetISOWeekYear,
     getWeeksInYear,
-    getISOWeeksInYear,
     getWeeksInWeekYear,
+    getISOWeeksInYear,
+    getISOWeeksInISOWeekYear,
 } from '../units/week-year';
 proto.weekYear = getSetWeekYear;
 proto.isoWeekYear = getSetISOWeekYear;
@@ -108,6 +109,7 @@ proto.isoWeek = proto.isoWeeks = getSetISOWeek;
 proto.weeksInYear = getWeeksInYear;
 proto.weeksInWeekYear = getWeeksInWeekYear;
 proto.isoWeeksInYear = getISOWeeksInYear;
+proto.isoWeeksInISOWeekYear = getISOWeeksInISOWeekYear;
 
 // Day
 import { getSetDayOfMonth } from '../units/day-of-month';
diff --git a/src/lib/units/week-year.js b/src/lib/units/week-year.js
index 7c60a36459..211b2e9b4c 100644
--- a/src/lib/units/week-year.js
+++ b/src/lib/units/week-year.js
@@ -99,6 +99,10 @@ export function getSetISOWeekYear(input) {
 }
 
 export function getISOWeeksInYear() {
+    return weeksInYear(this.year(), 1, 4);
+}
+
+export function getISOWeeksInISOWeekYear() {
     return weeksInYear(this.isoWeekYear(), 1, 4);
 }
 
diff --git a/src/test/moment/weeks_in_year.js b/src/test/moment/weeks_in_year.js
index b2a50057bc..6b20b177f8 100644
--- a/src/test/moment/weeks_in_year.js
+++ b/src/test/moment/weeks_in_year.js
@@ -3,89 +3,112 @@ import moment from '../../moment';
 
 module('weeks in year');
 
-test('isoWeeksInYear first day of ISO Year', function (assert) {
+test('isoWeeksInYear', function (assert) {
     assert.equal(
-        moment('2003-12-29').isoWeeksInYear(),
+        moment([2005]).isoWeeksInYear(),
+        52,
+        'ISO year 2005 has 52 iso weeks'
+    );
+    assert.equal(
+        moment([2006]).isoWeeksInYear(),
+        52,
+        'ISO year 2006 has 52 iso weeks'
+    );
+    assert.equal(
+        moment([2009]).isoWeeksInYear(),
+        53,
+        'ISO year 2009 has 53 iso weeks'
+    );
+    assert.equal(
+        moment([2010]).isoWeeksInYear(),
+        52,
+        'ISO year 2010 has 52 iso weeks'
+    );
+});
+
+test('isoWeeksInISOWeekYear first day of ISO Year', function (assert) {
+    assert.equal(
+        moment('2003-12-29').isoWeeksInISOWeekYear(),
         53,
         'ISO year 2004 has 53 iso weeks'
     );
     assert.equal(
-        moment('2005-01-03').isoWeeksInYear(),
+        moment('2005-01-03').isoWeeksInISOWeekYear(),
         52,
         'ISO year 2005 has 53 iso weeks'
     );
     assert.equal(
-        moment('2006-01-02').isoWeeksInYear(),
+        moment('2006-01-02').isoWeeksInISOWeekYear(),
         52,
         'ISO year 2006 has 53 iso weeks'
     );
     assert.equal(
-        moment('2007-01-01').isoWeeksInYear(),
+        moment('2007-01-01').isoWeeksInISOWeekYear(),
         52,
         'ISO year 2007 has 52 iso weeks'
     );
     assert.equal(
-        moment('2007-12-31').isoWeeksInYear(),
+        moment('2007-12-31').isoWeeksInISOWeekYear(),
         52,
         'ISO year 2008 has 53 iso weeks'
     );
     assert.equal(
-        moment('2008-12-29').isoWeeksInYear(),
+        moment('2008-12-29').isoWeeksInISOWeekYear(),
         53,
         'ISO year 2009 has 53 iso weeks'
     );
     assert.equal(
-        moment('2010-01-04').isoWeeksInYear(),
+        moment('2010-01-04').isoWeeksInISOWeekYear(),
         52,
         'ISO year 2010 has 52 iso weeks'
     );
     assert.equal(
-        moment('2011-01-03').isoWeeksInYear(),
+        moment('2011-01-03').isoWeeksInISOWeekYear(),
         52,
         'ISO year 2011 has 52 iso weeks'
     );
     assert.equal(
-        moment('2012-01-02').isoWeeksInYear(),
+        moment('2012-01-02').isoWeeksInISOWeekYear(),
         52,
         'ISO year 2012 has 52 iso weeks'
     );
     assert.equal(
-        moment('2012-12-31').isoWeeksInYear(),
+        moment('2012-12-31').isoWeeksInISOWeekYear(),
         52,
         'ISO year 2013 has 52 iso weeks'
     );
     assert.equal(
-        moment('2013-12-30').isoWeeksInYear(),
+        moment('2013-12-30').isoWeeksInISOWeekYear(),
         52,
         'ISO year 2014 has 52 iso weeks'
     );
     assert.equal(
-        moment('2014-12-29').isoWeeksInYear(),
+        moment('2014-12-29').isoWeeksInISOWeekYear(),
         53,
         'ISO year 2015 has 53 iso weeks'
     );
     assert.equal(
-        moment('2016-01-04').isoWeeksInYear(),
+        moment('2016-01-04').isoWeeksInISOWeekYear(),
         52,
         'ISO year 2016 has 52 iso weeks'
     );
     assert.equal(
-        moment('2017-01-02').isoWeeksInYear(),
+        moment('2017-01-02').isoWeeksInISOWeekYear(),
         52,
         'ISO year 2017 has 52 iso weeks'
     );
     assert.equal(
-        moment('2018-01-01').isoWeeksInYear(),
+        moment('2018-01-01').isoWeeksInISOWeekYear(),
         52,
         'ISO year 2018 has 52 iso weeks'
     );
     assert.equal(
-        moment('2018-12-31').isoWeeksInYear(),
+        moment('2018-12-31').isoWeeksInISOWeekYear(),
         52,
         'ISO year 2019 has 52 iso weeks'
     );
     assert.equal(
-        moment('2019-12-30').isoWeeksInYear(),
+        moment('2019-12-30').isoWeeksInISOWeekYear(),
         53,
         'ISO year 2020 has 53 iso weeks'
     );
@@ -179,17 +202,17 @@ test('weeksInYear doy/dow = 0/6', function (assert) {
 test('isoWeeksInYear calendar year !== ISO year', function (assert) {
     var m = moment('2010-01-01');
     assert.equal(
-        moment('2019-12-31').isoWeeksInYear(),
+        moment('2019-12-31').isoWeeksInISOWeekYear(),
         53,
         'December 31, 2019 is in ISO year 2020 and ISO year 2020 has 53 weeks'
     );
     assert.equal(
-        moment('2020-12-31').isoWeeksInYear(),
+        moment('2020-12-31').isoWeeksInISOWeekYear(),
         53,
         'December 31, 2020 is in ISO year 2020 and ISO year 2020 has 53 weeks'
     );
     assert.equal(
-        m.isoWeeksInYear(),
+        m.isoWeeksInISOWeekYear(),
         53,
         '2010-01-01 is isoWeekYear 2009, which has 53 iso weeks'
     );