diff --git a/src/constant.js b/src/constant.js
index a52c5ff40..2c9dd9aa0 100644
--- a/src/constant.js
+++ b/src/constant.js
@@ -28,9 +28,3 @@ export const INVALID_DATE_STRING = 'Invalid Date'
 // regex
 export const REGEX_PARSE = /^(\d{4})-?(\d{1,2})-?(\d{0,2})[^0-9]*(\d{1,2})?:?(\d{1,2})?:?(\d{1,2})?.?(\d{1,3})?$/
 export const REGEX_FORMAT = /\[.*?\]|Y{2,4}|M{1,4}|D{1,2}|d{1,4}|H{1,2}|h{1,2}|a|A|m{1,2}|s{1,2}|Z{1,2}|SSS/g
-
-export const en = {
-  name: 'en',
-  weekdays: 'Sunday_Monday_Tuesday_Wednesday_Thursday_Friday_Saturday'.split('_'),
-  months: 'January_February_March_April_May_June_July_August_September_October_November_December'.split('_')
-}
diff --git a/src/index.js b/src/index.js
index 49e5e440a..96cda316c 100644
--- a/src/index.js
+++ b/src/index.js
@@ -1,9 +1,10 @@
 import * as C from './constant'
 import U from './utils'
+import en from './locale/en'
 
 let L = 'en' // global locale
 const Ls = {} // global loaded locale
-Ls[L] = C.en
+Ls[L] = en
 
 const isDayjs = d => d instanceof Dayjs // eslint-disable-line no-use-before-define
 
diff --git a/src/locale/en.js b/src/locale/en.js
new file mode 100644
index 000000000..c4cd9b856
--- /dev/null
+++ b/src/locale/en.js
@@ -0,0 +1,5 @@
+export default {
+  name: 'en',
+  weekdays: 'Sunday_Monday_Tuesday_Wednesday_Thursday_Friday_Saturday'.split('_'),
+  months: 'January_February_March_April_May_June_July_August_September_October_November_December'.split('_')
+}
diff --git a/test/locale/keys.test.js b/test/locale/keys.test.js
index f779cab46..c22a86807 100644
--- a/test/locale/keys.test.js
+++ b/test/locale/keys.test.js
@@ -36,9 +36,12 @@ it('Locale keys', () => {
 
     expect(months).toEqual(expect.any(Array))
     // function pass date return string or number or null
-    for (let i = 1; i <= 31; i += 1) {
-      expect(ordinal(i)).toEqual(expect.anything())
+    if (name !== 'en') { // en ordinal set in advancedFormat
+      for (let i = 1; i <= 31; i += 1) {
+        expect(ordinal(i)).toEqual(expect.anything())
+      }
     }
+
     expect(dayjs().locale(name).$locale().name).toBe(name)
     if (formats) {
       expect(Object.keys(formats).sort()).toEqual(['L', 'LL', 'LLL', 'LLLL', 'LT', 'LTS'].sort())