diff --git a/app/src/main/assets/languagetool.json b/app/src/main/assets/languagetool.json
new file mode 100644
index 0000000000..13895f31bf
--- /dev/null
+++ b/app/src/main/assets/languagetool.json
@@ -0,0 +1,317 @@
+[
+  {
+    "name": "Arabic",
+    "code": "ar",
+    "longCode": "ar"
+  },
+  {
+    "name": "Asturian",
+    "code": "ast",
+    "longCode": "ast-ES"
+  },
+  {
+    "name": "Belarusian",
+    "code": "be",
+    "longCode": "be-BY"
+  },
+  {
+    "name": "Breton",
+    "code": "br",
+    "longCode": "br-FR"
+  },
+  {
+    "name": "Catalan",
+    "code": "ca",
+    "longCode": "ca-ES"
+  },
+  {
+    "name": "Catalan (Valencian)",
+    "code": "ca",
+    "longCode": "ca-ES-valencia"
+  },
+  {
+    "name": "Chinese",
+    "code": "zh",
+    "longCode": "zh-CN"
+  },
+  {
+    "name": "Danish",
+    "code": "da",
+    "longCode": "da-DK"
+  },
+  {
+    "name": "Dutch",
+    "code": "nl",
+    "longCode": "nl"
+  },
+  {
+    "name": "Dutch",
+    "code": "nl",
+    "longCode": "nl"
+  },
+  {
+    "name": "Dutch (Belgium)",
+    "code": "nl",
+    "longCode": "nl-BE"
+  },
+  {
+    "name": "English",
+    "code": "en",
+    "longCode": "en"
+  },
+  {
+    "name": "English",
+    "code": "en",
+    "longCode": "en"
+  },
+  {
+    "name": "English (Australian)",
+    "code": "en",
+    "longCode": "en-AU"
+  },
+  {
+    "name": "English (Australian)",
+    "code": "en",
+    "longCode": "en-AU"
+  },
+  {
+    "name": "English (Canadian)",
+    "code": "en",
+    "longCode": "en-CA"
+  },
+  {
+    "name": "English (Canadian)",
+    "code": "en",
+    "longCode": "en-CA"
+  },
+  {
+    "name": "English (GB)",
+    "code": "en",
+    "longCode": "en-GB"
+  },
+  {
+    "name": "English (GB)",
+    "code": "en",
+    "longCode": "en-GB"
+  },
+  {
+    "name": "English (New Zealand)",
+    "code": "en",
+    "longCode": "en-NZ"
+  },
+  {
+    "name": "English (New Zealand)",
+    "code": "en",
+    "longCode": "en-NZ"
+  },
+  {
+    "name": "English (South African)",
+    "code": "en",
+    "longCode": "en-ZA"
+  },
+  {
+    "name": "English (South African)",
+    "code": "en",
+    "longCode": "en-ZA"
+  },
+  {
+    "name": "English (US)",
+    "code": "en",
+    "longCode": "en-US"
+  },
+  {
+    "name": "English (US)",
+    "code": "en",
+    "longCode": "en-US"
+  },
+  {
+    "name": "Esperanto",
+    "code": "eo",
+    "longCode": "eo"
+  },
+  {
+    "name": "French",
+    "code": "fr",
+    "longCode": "fr"
+  },
+  {
+    "name": "French",
+    "code": "fr",
+    "longCode": "fr"
+  },
+  {
+    "name": "Galician",
+    "code": "gl",
+    "longCode": "gl-ES"
+  },
+  {
+    "name": "German",
+    "code": "de",
+    "longCode": "de"
+  },
+  {
+    "name": "German",
+    "code": "de",
+    "longCode": "de"
+  },
+  {
+    "name": "German (Austria)",
+    "code": "de",
+    "longCode": "de-AT"
+  },
+  {
+    "name": "German (Austria)",
+    "code": "de",
+    "longCode": "de-AT"
+  },
+  {
+    "name": "German (Germany)",
+    "code": "de",
+    "longCode": "de-DE"
+  },
+  {
+    "name": "German (Germany)",
+    "code": "de",
+    "longCode": "de-DE"
+  },
+  {
+    "name": "German (Swiss)",
+    "code": "de",
+    "longCode": "de-CH"
+  },
+  {
+    "name": "German (Swiss)",
+    "code": "de",
+    "longCode": "de-CH"
+  },
+  {
+    "name": "Greek",
+    "code": "el",
+    "longCode": "el-GR"
+  },
+  {
+    "name": "Irish",
+    "code": "ga",
+    "longCode": "ga-IE"
+  },
+  {
+    "name": "Italian",
+    "code": "it",
+    "longCode": "it"
+  },
+  {
+    "name": "Japanese",
+    "code": "ja",
+    "longCode": "ja-JP"
+  },
+  {
+    "name": "Khmer",
+    "code": "km",
+    "longCode": "km-KH"
+  },
+  {
+    "name": "Norwegian (Bokmål)",
+    "code": "nb",
+    "longCode": "nb"
+  },
+  {
+    "name": "Norwegian (Bokmål)",
+    "code": "no",
+    "longCode": "no"
+  },
+  {
+    "name": "Persian",
+    "code": "fa",
+    "longCode": "fa"
+  },
+  {
+    "name": "Polish",
+    "code": "pl",
+    "longCode": "pl-PL"
+  },
+  {
+    "name": "Portuguese",
+    "code": "pt",
+    "longCode": "pt"
+  },
+  {
+    "name": "Portuguese (Angola preAO)",
+    "code": "pt",
+    "longCode": "pt-AO"
+  },
+  {
+    "name": "Portuguese (Brazil)",
+    "code": "pt",
+    "longCode": "pt-BR"
+  },
+  {
+    "name": "Portuguese (Moçambique preAO)",
+    "code": "pt",
+    "longCode": "pt-MZ"
+  },
+  {
+    "name": "Portuguese (Portugal)",
+    "code": "pt",
+    "longCode": "pt-PT"
+  },
+  {
+    "name": "Romanian",
+    "code": "ro",
+    "longCode": "ro-RO"
+  },
+  {
+    "name": "Russian",
+    "code": "ru",
+    "longCode": "ru-RU"
+  },
+  {
+    "name": "Simple German",
+    "code": "de-DE-x-simple-language",
+    "longCode": "de-DE-x-simple-language"
+  },
+  {
+    "name": "Slovak",
+    "code": "sk",
+    "longCode": "sk-SK"
+  },
+  {
+    "name": "Slovenian",
+    "code": "sl",
+    "longCode": "sl-SI"
+  },
+  {
+    "name": "Spanish",
+    "code": "es",
+    "longCode": "es"
+  },
+  {
+    "name": "Spanish",
+    "code": "es",
+    "longCode": "es"
+  },
+  {
+    "name": "Spanish (voseo)",
+    "code": "es",
+    "longCode": "es-AR"
+  },
+  {
+    "name": "Swedish",
+    "code": "sv",
+    "longCode": "sv"
+  },
+  {
+    "name": "Tagalog",
+    "code": "tl",
+    "longCode": "tl-PH"
+  },
+  {
+    "name": "Tamil",
+    "code": "ta",
+    "longCode": "ta-IN"
+  },
+  {
+    "name": "Ukrainian",
+    "code": "uk",
+    "longCode": "uk-UA"
+  }
+]
\ No newline at end of file
diff --git a/app/src/main/java/eu/faircode/email/LanguageTool.java b/app/src/main/java/eu/faircode/email/LanguageTool.java
index d8c46b1c90..031add72fd 100644
--- a/app/src/main/java/eu/faircode/email/LanguageTool.java
+++ b/app/src/main/java/eu/faircode/email/LanguageTool.java
@@ -45,9 +45,29 @@ public class LanguageTool {
         // https://languagetool.org/http-api/swagger-ui/#!/default/post_check
         String request =
                 "text=" + URLEncoder.encode(text.toString(), StandardCharsets.UTF_8.name()) +
-                        "&language=auto" +
-                        "&preferredVariants=" + Locale.getDefault().toLanguageTag();
-        Log.i("LT request=" + request);
+                        "&language=auto";
+
+        // curl -X GET --header 'Accept: application/json' 'https://api.languagetool.org/v2/languages
+        String code = null;
+        JSONArray jlanguages;
+        Locale locale = Locale.getDefault();
+        try (InputStream is = context.getAssets().open("languagetool.json")) {
+            String json = Helper.readStream(is);
+            jlanguages = new JSONArray(json);
+        }
+        for (int i = 0; i < jlanguages.length(); i++) {
+            JSONObject jlanguage = jlanguages.getJSONObject(i);
+            String c = jlanguage.optString("longCode");
+            if (locale.toLanguageTag().equals(c) && c.contains("-")) {
+                code = c;
+                break;
+            }
+        }
+
+        if (code != null)
+            request += "&preferredVariants=" + code;
+
+        Log.i("LT locale=" + locale + " request=" + request);
 
         URL url = new URL(LT_URI + "check");
         HttpsURLConnection connection = (HttpsURLConnection) url.openConnection();