diff --git a/lunaria/prepare-json-files.ts b/lunaria/prepare-json-files.ts
index 1011514cb3..127c8aa0fa 100644
--- a/lunaria/prepare-json-files.ts
+++ b/lunaria/prepare-json-files.ts
@@ -88,7 +88,7 @@ async function mergeLocale(locale: LocaleObject): Promise<void> {
 
   await fs.writeFile(
     path.resolve(`${destFolder}/${locale.code}.json`),
-    JSON.stringify(source, null, 2),
+    `${JSON.stringify(source, null, 2)}\n`,
     'utf-8',
   )
 }
diff --git a/scripts/compare-translations.ts b/scripts/compare-translations.ts
index ad4a98acfd..5e95a042b5 100644
--- a/scripts/compare-translations.ts
+++ b/scripts/compare-translations.ts
@@ -209,12 +209,25 @@ const logSection = (
 }
 
 const processLocale = async (
+  singleLocale: boolean,
   localeFile: string,
   referenceContent: NestedObject,
   fix = false,
 ): Promise<SyncStats> => {
   const filePath = join(LOCALES_DIRECTORY, localeFile)
   const localeInfo = checkJsonName(filePath)
+
+  // prevent updating wrong locale file:
+  // - language locale files at countries allowed: e.g. es.json
+  // - country locale file forbidden: e.g. es-ES.json
+  // - target locale file forbidden: e.g. es-419.json
+  if (fix && localeInfo.mergeLocale && singleLocale) {
+    console.error(
+      `${COLORS.red}Error: Locale "${localeInfo.locale}" cannot be fixed, fix the ${localeInfo.lang} locale instead!${COLORS.reset}`,
+    )
+    process.exit(1)
+  }
+
   const targetContent = await loadJson(localeInfo)
 
   const stats: SyncStats = {
@@ -226,7 +239,7 @@ const processLocale = async (
   const newContent = syncLocaleData(referenceContent, targetContent, stats, fix)
 
   // Write if there are removals (always) or we are in fix mode
-  if (stats.extra.length > 0 || fix) {
+  if (!localeInfo.mergeLocale && (stats.extra.length > 0 || fix)) {
     writeFileSync(filePath, JSON.stringify(newContent, null, 2) + '\n', 'utf-8')
   }
 
@@ -246,7 +259,12 @@ const runSingleLocale = async (
     process.exit(1)
   }
 
-  const { missing, extra, referenceKeys } = await processLocale(localeFile, referenceContent, fix)
+  const { missing, extra, referenceKeys } = await processLocale(
+    true,
+    localeFile,
+    referenceContent,
+    fix,
+  )
 
   console.log(
     `${COLORS.cyan}=== Missing keys for ${localeFile}${fix ? ' (with --fix)' : ''} ===${COLORS.reset}`,
@@ -286,7 +304,7 @@ const runAllLocales = async (referenceContent: NestedObject, fix = false): Promi
   let totalAdded = 0
 
   for (const localeFile of localeFiles) {
-    const stats = await processLocale(localeFile, referenceContent, fix)
+    const stats = await processLocale(false, localeFile, referenceContent, fix)
     results.push({
       file: localeFile,
       ...stats,