diff --git a/CHANGELOG.md b/CHANGELOG.md
index adabd7d8..8d109585 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,9 @@
 # Changelog
 
+## [v1.21.1](https://github.com/contentstack/contentstack-management-javascript/tree/v1.21.1) (2025-05-12)
+ - Fix
+   - Fixed unexpected fallback_locale behavior during direct locale updates.
+
 ## [v1.21.0](https://github.com/contentstack/contentstack-management-javascript/tree/v1.21.0) (2025-05-05)
  - Enhancement
     - Region support added
diff --git a/lib/entity.js b/lib/entity.js
index 6fcb22ff..5fe29f3a 100644
--- a/lib/entity.js
+++ b/lib/entity.js
@@ -155,7 +155,12 @@ export const update = (http, type, params = {}) => {
     delete json.deleted_at
     delete json.updated_at
     delete json.updated_by
-    delete json.updated_at
+
+    // If param has data for this entity type, merge it with the json object
+    if (param && param[type]) {
+      Object.assign(json, param[type])
+    }
+
     if (type) {
       updateData[type] = json
       if (type === 'entry') updateData[type] = cleanAssets(updateData[type])
diff --git a/package-lock.json b/package-lock.json
index 50fa7f36..bb6d54f9 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "@contentstack/management",
-  "version": "1.21.0",
+  "version": "1.21.1",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "@contentstack/management",
-      "version": "1.21.0",
+      "version": "1.21.1",
       "license": "MIT",
       "dependencies": {
         "assert": "^2.1.0",
diff --git a/package.json b/package.json
index 51587221..7c66afdd 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@contentstack/management",
-  "version": "1.21.0",
+  "version": "1.21.1",
   "description": "The Content Management API is used to manage the content of your Contentstack account",
   "main": "./dist/node/contentstack-management.js",
   "browser": "./dist/web/contentstack-management.js",
diff --git a/sanity-report.mjs b/sanity-report.mjs
index 2847a04d..5732fc77 100644
--- a/sanity-report.mjs
+++ b/sanity-report.mjs
@@ -5,7 +5,7 @@ import fs from 'fs'
 
 dotenv.config()
 
-const mochawesomeJsonOutput = fs.readFileSync('./mochawesome-report/mochawesome.json', 'utf-8')
+const mochawesomeJsonOutput = fs.readFileSync('./mochawesome-report/mochawesome.json', 'utf8')
 const mochawesomeReport = JSON.parse(mochawesomeJsonOutput)
 const report = `./mochawesome-report/sanity-report.html`
 
diff --git a/test/sanity-check/api/locale-test.js b/test/sanity-check/api/locale-test.js
index 913a5188..7623c661 100644
--- a/test/sanity-check/api/locale-test.js
+++ b/test/sanity-check/api/locale-test.js
@@ -94,12 +94,12 @@ describe('Locale api Test', () => {
       .catch(done)
   })
 
-  it('should get and update a language Hindi - India', done => {
+  it('should get and update a language Hindi - India with fallback locale en-at', done => {
     makeLocale('hi-in')
       .fetch()
       .then((locale) => {
-        locale.fallback_locale = 'en-at'
-        return locale.update()
+        // locale.fallback_locale = 'en-at'
+        return locale.update({ locale: { fallback_locale: 'en-at' } })
       })
       .then((locale) => {
         expect(locale.code).to.be.equal('hi-in')
@@ -111,6 +111,23 @@ describe('Locale api Test', () => {
       .catch(done)
   })
 
+  it('should get and update a language Hindi - India with fallback locale en-us', done => {
+    makeLocale('hi-in')
+      .fetch()
+      .then((locale) => {
+        locale.fallback_locale = 'en-us'
+        return locale.update()
+      })
+      .then((locale) => {
+        expect(locale.code).to.be.equal('hi-in')
+        expect(locale.name).to.be.equal('Hindi - India')
+        expect(locale.fallback_locale).to.be.equal('en-us')
+        expect(locale.uid).to.be.not.equal(null)
+        done()
+      })
+      .catch(done)
+  })
+
   it('should delete language: Hindi - India', done => {
     makeLocale('mr-in')
       .delete()