diff --git a/ext/data/schemas/dictionary-index-schema.json b/ext/data/schemas/dictionary-index-schema.json
index 56726668c3..27d525c7b8 100644
--- a/ext/data/schemas/dictionary-index-schema.json
+++ b/ext/data/schemas/dictionary-index-schema.json
@@ -1,6 +1,13 @@
 {
     "$id": "dictionaryIndex",
     "$schema": "http://json-schema.org/draft-07/schema#",
+    "definitions": {
+        "isoLanguageCode": {
+            "type": "string",
+            "description": "ISO language code (ISO 639-1 where possible, ISO 639-3 otherwise).",
+            "pattern": "^(aa|ab|ae|af|ak|am|an|ar|as|av|ay|az|az|ba|be|bg|bh|bi|bm|bn|bo|br|bs|ca|ce|ch|co|cr|cs|cu|cv|cy|da|de|dv|dz|ee|el|en|eo|es|et|eu|fa|ff|fi|fj|fo|fr|fy|ga|gd|gl|gn|grc|gu|gv|ha|he|hi|ho|hr|ht|hu|hy|hz|ia|id|ie|ig|ii|ik|io|is|it|iu|ja|jv|ka|kg|ki|kj|kk|kl|km|kn|ko|kr|ks|ku|kv|kw|ky|la|lb|lg|li|ln|lo|lt|lu|lv|mg|mh|mi|mk|ml|mn|mr|ms|mt|my|na|nb|nd|ne|ng|nl|nn|no|nr|nv|ny|oc|oj|om|or|os|pa|pi|pl|ps|pt|qu|rm|rn|ro|ru|rw|sa|sc|sd|se|sg|si|sk|sl|sm|sn|so|sq|sr|ss|st|su|sv|sw|ta|te|tg|th|ti|tk|tl|tn|to|tr|ts|tt|tw|ty|ug|uk|ur|uz|ve|vi|vo|wa|wo|xh|yi|yo|za|zh|zu)$"
+        }
+    },
     "type": "object",
     "description": "Index file containing information about the data contained in the dictionary.",
     "required": [
@@ -47,6 +54,14 @@
             "type": "string",
             "description": "Attribution information for the dictionary data."
         },
+        "sourceLanguage": {
+            "$ref": "#/definitions/isoLanguageCode",
+            "description": "Language of the terms in the dictionary."
+        },
+        "targetLanguage": {
+            "$ref": "#/definitions/isoLanguageCode",
+            "description": "Main language of the definitions in the dictionary."
+        },
         "frequencyMode": {
             "type": "string",
             "enum": ["occurrence-based", "rank-based"]
diff --git a/ext/js/dictionary/dictionary-importer.js b/ext/js/dictionary/dictionary-importer.js
index 310b2ec141..f0c92481c5 100644
--- a/ext/js/dictionary/dictionary-importer.js
+++ b/ext/js/dictionary/dictionary-importer.js
@@ -285,12 +285,14 @@ export class DictionaryImporter {
             counts
         };
 
-        const {author, url, description, attribution, frequencyMode} = index;
+        const {author, url, description, attribution, frequencyMode, sourceLanguage, targetLanguage} = index;
         if (typeof author === 'string') { summary.author = author; }
         if (typeof url === 'string') { summary.url = url; }
         if (typeof description === 'string') { summary.description = description; }
         if (typeof attribution === 'string') { summary.attribution = attribution; }
         if (typeof frequencyMode === 'string') { summary.frequencyMode = frequencyMode; }
+        if (typeof sourceLanguage === 'string') { summary.sourceLanguage = sourceLanguage; }
+        if (typeof targetLanguage === 'string') { summary.targetLanguage = targetLanguage; }
 
         return summary;
     }
diff --git a/ext/js/pages/settings/dictionary-controller.js b/ext/js/pages/settings/dictionary-controller.js
index a0e0c19634..f0450892b9 100644
--- a/ext/js/pages/settings/dictionary-controller.js
+++ b/ext/js/pages/settings/dictionary-controller.js
@@ -211,12 +211,14 @@ class DictionaryEntry {
      * @returns {boolean}
      */
     _setupDetails(detailsTable) {
-        /** @type {[label: string, key: 'author'|'url'|'description'|'attribution'][]} */
+        /** @type {[label: string, key: 'author'|'url'|'description'|'attribution'|'sourceLanguage'|'targetLanguage'][]} */
         const targets = [
             ['Author', 'author'],
             ['URL', 'url'],
             ['Description', 'description'],
-            ['Attribution', 'attribution']
+            ['Attribution', 'attribution'],
+            ['Source Language', 'sourceLanguage'],
+            ['Target Language', 'targetLanguage']
         ];
 
         const dictionaryInfo = this._dictionaryInfo;
diff --git a/types/ext/dictionary-data.d.ts b/types/ext/dictionary-data.d.ts
index 0128f83f7e..68752bbb2e 100644
--- a/types/ext/dictionary-data.d.ts
+++ b/types/ext/dictionary-data.d.ts
@@ -29,6 +29,8 @@ export type Index = {
     url?: string;
     description?: string;
     attribution?: string;
+    sourceLanguage?: string;
+    targetLanguage?: string;
     frequencyMode?: 'occurrence-based' | 'rank-based';
     tagMeta?: IndexTagMeta;
 };
diff --git a/types/ext/dictionary-importer.d.ts b/types/ext/dictionary-importer.d.ts
index 3a320f969a..8807b3bcfc 100644
--- a/types/ext/dictionary-importer.d.ts
+++ b/types/ext/dictionary-importer.d.ts
@@ -65,6 +65,8 @@ export type Summary = {
     url?: string;
     description?: string;
     attribution?: string;
+    sourceLanguage?: string;
+    targetLanguage?: string;
     frequencyMode?: 'occurrence-based' | 'rank-based';
 };