diff --git a/src/locale/en.js b/src/locale/en.js
index 76cc04fbd..a9eb16369 100644
--- a/src/locale/en.js
+++ b/src/locale/en.js
@@ -1,8 +1,6 @@
+// We don't need weekdaysShort, weekdaysMin, monthsShort in en.js locale
 export default {
   name: 'en',
   weekdays: 'Sunday_Monday_Tuesday_Wednesday_Thursday_Friday_Saturday'.split('_'),
-  weekdaysShort: 'Sun_Mon_Tue_Wed_Thu_Fri_Sat'.split('_'),
-  weekdaysMin: 'Su_Mo_Tu_We_Th_Fr_Sa'.split('_'),
-  months: 'January_February_March_April_May_June_July_August_September_October_November_December'.split('_'),
-  monthsShort: 'Jan_Feb_Mar_Apr_May_Jun_Jul_Aug_Sep_Oct_Nov_Dec'.split('_')
+  months: 'January_February_March_April_May_June_July_August_September_October_November_December'.split('_')
 }
diff --git a/src/plugin/localeData/index.js b/src/plugin/localeData/index.js
index c49a1117e..c8008a22d 100644
--- a/src/plugin/localeData/index.js
+++ b/src/plugin/localeData/index.js
@@ -1,16 +1,23 @@
 export default (o, c, dayjs) => { // locale needed later
   const proto = c.prototype
+  const getShort = (ins, target, full, num) => {
+    const locale = ins.$locale()
+    if (!locale[target]) {
+      return locale[full].map(f => f.substr(0, num))
+    }
+    return locale[target]
+  }
   const localeData = function () {
     return {
       months: instance =>
-        (instance ? instance.format('MMMM') : this.$locale().months),
+        (instance ? instance.format('MMMM') : getShort(this, 'months')),
       monthsShort: instance =>
-        (instance ? instance.format('MMM') : this.$locale().monthsShort),
+        (instance ? instance.format('MMM') : getShort(this, 'monthsShort', 'months', 3)),
       firstDayOfWeek: () => this.$locale().weekStart || 0,
       weekdaysMin: instance =>
-        (instance ? instance.format('dd') : this.$locale().weekdaysMin),
+        (instance ? instance.format('dd') : getShort(this, 'weekdaysMin', 'weekdays', 2)),
       weekdaysShort: instance =>
-        (instance ? instance.format('ddd') : this.$locale().weekdaysShort)
+        (instance ? instance.format('ddd') : getShort(this, 'weekdaysShort', 'weekdays', 3))
     }
   }
   proto.localeData = function () {
diff --git a/test/display.test.js b/test/display.test.js
index 6c546d923..42975c3cb 100644
--- a/test/display.test.js
+++ b/test/display.test.js
@@ -248,6 +248,7 @@ it('As Javascript Date -> toDate', () => {
 
 it('As JSON -> toJSON', () => {
   expect(dayjs().toJSON()).toBe(moment().toJSON())
+  global.console.warn = jest.genMockFunction()// moment.js otherString will throw warn
   expect(dayjs('otherString').toJSON()).toBe(moment('otherString').toJSON())
   expect(dayjs('otherString').toJSON()).toBe(null)
 })