diff --git a/invenio_vocabularies/contrib/subjects/mappings/os-v1/subjects/subject-v1.0.0.json b/invenio_vocabularies/contrib/subjects/mappings/os-v1/subjects/subject-v1.0.0.json
index 393f01c8..4da78257 100644
--- a/invenio_vocabularies/contrib/subjects/mappings/os-v1/subjects/subject-v1.0.0.json
+++ b/invenio_vocabularies/contrib/subjects/mappings/os-v1/subjects/subject-v1.0.0.json
@@ -71,6 +71,7 @@
       },
       "synonyms": {
         "type": "array"
+      },
       "tags": {
         "type": "keyword"
       }
diff --git a/invenio_vocabularies/contrib/subjects/mappings/os-v2/subjects/subject-v1.0.0.json b/invenio_vocabularies/contrib/subjects/mappings/os-v2/subjects/subject-v1.0.0.json
index 393f01c8..4da78257 100644
--- a/invenio_vocabularies/contrib/subjects/mappings/os-v2/subjects/subject-v1.0.0.json
+++ b/invenio_vocabularies/contrib/subjects/mappings/os-v2/subjects/subject-v1.0.0.json
@@ -71,6 +71,7 @@
       },
       "synonyms": {
         "type": "array"
+      },
       "tags": {
         "type": "keyword"
       }
diff --git a/invenio_vocabularies/contrib/subjects/mappings/v7/subjects/subject-v1.0.0.json b/invenio_vocabularies/contrib/subjects/mappings/v7/subjects/subject-v1.0.0.json
index 74646df7..4da78257 100644
--- a/invenio_vocabularies/contrib/subjects/mappings/v7/subjects/subject-v1.0.0.json
+++ b/invenio_vocabularies/contrib/subjects/mappings/v7/subjects/subject-v1.0.0.json
@@ -70,7 +70,8 @@
         }
       },
       "synonyms": {
-        "type": "text"
+        "type": "array"
+      },
       "tags": {
         "type": "keyword"
       }