diff --git a/Tekst-API/openapi.json b/Tekst-API/openapi.json
index ea8cfadc..183cdc40 100644
--- a/Tekst-API/openapi.json
+++ b/Tekst-API/openapi.json
@@ -9968,54 +9968,22 @@
           "sourceLanguage": {
             "anyOf": [
               {
-                "$ref": "#/components/schemas/DeepLSourceLanguage"
+                "type": "null"
               },
               {
-                "type": "null"
+                "type": "string",
+                "maxLength": 16,
+                "minLength": 1
               }
             ],
-            "description": "Source language"
+            "title": "Sourcelanguage",
+            "description": "DeepL source language code"
           }
         },
         "type": "object",
         "title": "DeepLLinksConfig",
         "description": "Resource configuration model for DeepL translation links.\nThe corresponding field MUST be named `deepl_links`!"
       },
-      "DeepLSourceLanguage": {
-        "type": "string",
-        "enum": [
-          "ar",
-          "bg",
-          "cs",
-          "da",
-          "de",
-          "el",
-          "en",
-          "es",
-          "et",
-          "fi",
-          "fr",
-          "hu",
-          "id",
-          "it",
-          "ja",
-          "ko",
-          "lt",
-          "lv",
-          "nb",
-          "nl",
-          "pl",
-          "pt",
-          "ro",
-          "ru",
-          "sk",
-          "sl",
-          "sv",
-          "tr",
-          "uk",
-          "zh"
-        ]
-      },
       "DeleteLocationResult": {
         "properties": {
           "contents": {
diff --git a/Tekst-API/tekst/resources/plain_text.py b/Tekst-API/tekst/resources/plain_text.py
index a0e44ab4..708a5889 100644
--- a/Tekst-API/tekst/resources/plain_text.py
+++ b/Tekst-API/tekst/resources/plain_text.py
@@ -3,7 +3,7 @@
 from pathlib import Path
 from typing import Annotated, Any, Literal
 
-from pydantic import Field
+from pydantic import AfterValidator, Field
 
 from tekst.models.common import ModelBase
 from tekst.models.content import ContentBase
@@ -19,6 +19,7 @@
 from tekst.resources import ResourceSearchQuery, ResourceTypeABC
 from tekst.types import (
     ConStr,
+    ConStrOrNone,
     ContentCssProperties,
     SchemaOptionalNullable,
     SearchReplacements,
@@ -186,40 +187,6 @@ class LineLabellingConfig(ModelBase):
     ] = "numbersOneBased"
 
 
-type DeepLSourceLanguage = Literal[
-    "ar",
-    "bg",
-    "cs",
-    "da",
-    "de",
-    "el",
-    "en",
-    "es",
-    "et",
-    "fi",
-    "fr",
-    "hu",
-    "id",
-    "it",
-    "ja",
-    "ko",
-    "lt",
-    "lv",
-    "nb",
-    "nl",
-    "pl",
-    "pt",
-    "ro",
-    "ru",
-    "sk",
-    "sl",
-    "sv",
-    "tr",
-    "uk",
-    "zh",
-]
-
-
 class DeepLLinksConfig(ModelBase):
     """
     Resource configuration model for DeepL translation links.
@@ -233,10 +200,14 @@ class DeepLLinksConfig(ModelBase):
         ),
     ] = False
     source_language: Annotated[
-        DeepLSourceLanguage | None,
+        ConStrOrNone(
+            max_length=16,
+            cleanup="oneline",
+        ),
         Field(
-            description="Source language",
+            description="DeepL source language code",
         ),
+        AfterValidator(lambda x: x.lower() if x else None),
     ] = None
 
 
diff --git a/Tekst-Web/src/api/index.ts b/Tekst-Web/src/api/index.ts
index aef77bdd..9b4ffcd9 100644
--- a/Tekst-Web/src/api/index.ts
+++ b/Tekst-Web/src/api/index.ts
@@ -162,72 +162,244 @@ export const resourceTypes = [
 ];
 
 export const deeplSourceLanguages = [
+  'ace',
+  'af',
+  'an',
   'ar',
+  'as',
+  'ay',
+  'az',
+  'ba',
+  'be',
   'bg',
+  'bho',
+  'bn',
+  'br',
+  'bs',
+  'ca',
+  'ceb',
+  'ckb',
   'cs',
+  'cy',
   'da',
   'de',
   'el',
   'en',
+  'eo',
   'es',
   'et',
+  'eu',
+  'fa',
   'fi',
   'fr',
+  'ga',
+  'gl',
+  'gn',
+  'gom',
+  'gu',
+  'ha',
+  'he',
+  'hi',
+  'hr',
+  'ht',
   'hu',
+  'hy',
   'id',
+  'ig',
+  'is',
   'it',
   'ja',
+  'jv',
+  'ka',
+  'kk',
+  'kmr',
   'ko',
+  'ky',
+  'la',
+  'lb',
+  'lmo',
+  'ln',
   'lt',
   'lv',
+  'mai',
+  'mg',
+  'mi',
+  'mk',
+  'ml',
+  'mn',
+  'mr',
+  'ms',
+  'mt',
+  'my',
   'nb',
+  'ne',
   'nl',
+  'oc',
+  'om',
+  'pa',
+  'pag',
+  'pam',
   'pl',
+  'prs',
+  'ps',
   'pt',
+  'qu',
   'ro',
   'ru',
+  'sa',
+  'scn',
   'sk',
   'sl',
+  'sq',
+  'sr',
+  'st',
+  'su',
   'sv',
+  'sw',
+  'ta',
+  'te',
+  'tg',
+  'th',
+  'tk',
+  'tl',
+  'tn',
   'tr',
+  'ts',
+  'tt',
   'uk',
+  'ur',
+  'uz',
+  'vi',
+  'wo',
+  'xh',
+  'yi',
+  'yue',
   'zh',
+  'zu',
 ];
 
 export const deeplTargetLanguages = [
+  'ace',
+  'af',
+  'an',
   'ar',
+  'as',
+  'ay',
+  'az',
+  'ba',
+  'be',
   'bg',
+  'bho',
+  'bn',
+  'br',
+  'bs',
+  'ca',
+  'ceb',
+  'ckb',
   'cs',
+  'cy',
   'da',
   'de',
   'el',
+  'en',
   'en-gb',
   'en-us',
+  'eo',
   'es',
+  'es-419',
   'et',
+  'eu',
+  'fa',
   'fi',
   'fr',
+  'ga',
+  'gl',
+  'gn',
+  'gom',
+  'gu',
+  'ha',
+  'he',
+  'hi',
+  'hr',
+  'ht',
   'hu',
+  'hy',
   'id',
+  'ig',
+  'is',
   'it',
   'ja',
+  'jv',
+  'ka',
+  'kk',
+  'kmr',
   'ko',
+  'ky',
+  'la',
+  'lb',
+  'lmo',
+  'ln',
   'lt',
   'lv',
+  'mai',
+  'mg',
+  'mi',
+  'mk',
+  'ml',
+  'mn',
+  'mr',
+  'ms',
+  'mt',
+  'my',
   'nb',
+  'ne',
   'nl',
+  'oc',
+  'om',
+  'pa',
+  'pag',
+  'pam',
   'pl',
+  'prs',
+  'ps',
+  'pt',
   'pt-br',
   'pt-pt',
+  'qu',
   'ro',
   'ru',
+  'sa',
+  'scn',
   'sk',
   'sl',
+  'sq',
+  'sr',
+  'st',
+  'su',
   'sv',
+  'sw',
+  'ta',
+  'te',
+  'tg',
+  'th',
+  'tk',
+  'tl',
+  'tn',
   'tr',
+  'ts',
+  'tt',
   'uk',
+  'ur',
+  'uz',
+  'vi',
+  'wo',
+  'xh',
+  'yi',
+  'yue',
+  'zh',
   'zh-hans',
   'zh-hant',
+  'zu',
 ];
 
 // export components types for use throughout codebase
diff --git a/Tekst-Web/src/api/schema.d.ts b/Tekst-Web/src/api/schema.d.ts
index c66aebc5..b3c3d59c 100644
--- a/Tekst-Web/src/api/schema.d.ts
+++ b/Tekst-Web/src/api/schema.d.ts
@@ -2536,41 +2536,12 @@ export interface components {
        * @default false
        */
       enabled: boolean;
-      /** @description Source language */
-      sourceLanguage?: components['schemas']['DeepLSourceLanguage'] | null;
+      /**
+       * Sourcelanguage
+       * @description DeepL source language code
+       */
+      sourceLanguage?: null | string;
     };
-    /** @enum {string} */
-    DeepLSourceLanguage:
-      | 'ar'
-      | 'bg'
-      | 'cs'
-      | 'da'
-      | 'de'
-      | 'el'
-      | 'en'
-      | 'es'
-      | 'et'
-      | 'fi'
-      | 'fr'
-      | 'hu'
-      | 'id'
-      | 'it'
-      | 'ja'
-      | 'ko'
-      | 'lt'
-      | 'lv'
-      | 'nb'
-      | 'nl'
-      | 'pl'
-      | 'pt'
-      | 'ro'
-      | 'ru'
-      | 'sk'
-      | 'sl'
-      | 'sv'
-      | 'tr'
-      | 'uk'
-      | 'zh';
     /** DeleteLocationResult */
     DeleteLocationResult: {
       /** Contents */