diff --git a/services/src/main/java/org/exoplatform/onlyoffice/OnlyofficeEditorServiceImpl.java b/services/src/main/java/org/exoplatform/onlyoffice/OnlyofficeEditorServiceImpl.java
index 7e94e248e..36ce8aca9 100644
--- a/services/src/main/java/org/exoplatform/onlyoffice/OnlyofficeEditorServiceImpl.java
+++ b/services/src/main/java/org/exoplatform/onlyoffice/OnlyofficeEditorServiceImpl.java
@@ -2476,7 +2476,12 @@ public static String getUserLanguage(String userId) {
     String lang = Locale.getDefault().getLanguage();
     if(localePolicy != null) {
       Locale locale = localePolicy.determineLocale(localeCtx);
-      lang = locale.getLanguage() + "-" + locale.getCountry();
+      lang = locale.getLanguage();
+      // In case of pt_PT or cn_TW we have to add the country
+      // as detailed in https://api.onlyoffice.com/editors/config/editor#lang
+      if("PT".equalsIgnoreCase(locale.getCountry()) || "TW".equalsIgnoreCase(locale.getCountry())) {
+        lang = locale.getLanguage() + "-" + locale.getCountry();
+      }
     }
     return lang;
   }