diff --git a/meilisearch-core/src/update/settings_update.rs b/meilisearch-core/src/update/settings_update.rs
index 2be2e734e..452d2f3f1 100644
--- a/meilisearch-core/src/update/settings_update.rs
+++ b/meilisearch-core/src/update/settings_update.rs
@@ -45,7 +45,13 @@ pub fn apply_settings_update(
     match settings.ranking_rules {
         UpdateState::Update(v) => {
             let ranked_field: Vec<&str> = v.iter().filter_map(RankingRule::field).collect();
-            schema.update_ranked(ranked_field)?;
+            schema.update_ranked(&ranked_field)?;
+            for name in ranked_field {
+                if schema.accept_new_fields() {
+                    schema.set_indexed(name.as_ref())?;
+                    schema.set_displayed(name.as_ref())?;
+                }
+            }
             index.main.put_ranking_rules(writer, &v)?;
             must_reindex = true;
         },
diff --git a/meilisearch-http/tests/settings.rs b/meilisearch-http/tests/settings.rs
index 7e2b1275d..e2b57ee31 100644
--- a/meilisearch-http/tests/settings.rs
+++ b/meilisearch-http/tests/settings.rs
@@ -427,5 +427,4 @@ fn write_setting_and_update_partial() {
     let (response, _status_code) = server.get_all_settings();
 
     assert_json_eq!(expected, response, ordered: false);
-
 }
diff --git a/meilisearch-http/tests/settings_ranking_rules.rs b/meilisearch-http/tests/settings_ranking_rules.rs
index a393374ee..f203216ff 100644
--- a/meilisearch-http/tests/settings_ranking_rules.rs
+++ b/meilisearch-http/tests/settings_ranking_rules.rs
@@ -135,3 +135,54 @@ fn send_malformed_custom_rule() {
     let (_response, status_code) = server.update_ranking_rules_sync(body);
     assert_eq!(status_code, 400);
 }
+
+// Test issue https://github.com/meilisearch/MeiliSearch/issues/521
+#[test]
+fn write_custom_ranking_and_index_documents() {
+    let mut server = common::Server::with_uid("movies");
+    let body = json!({
+        "uid": "movies",
+        "primaryKey": "id",
+    });
+    server.create_index(body);
+
+    // 1 - Add ranking rules with one custom ranking on a string
+
+    let body = json!([
+        "asc(title)",
+        "typo"
+    ]);
+
+    server.update_ranking_rules(body);
+
+    // 2 - Add documents
+
+    let body = json!([
+      {
+        "id": 1,
+        "title": "Le Petit Prince",
+        "author": "Exupéry"
+      },
+      {
+        "id": 2,
+        "title": "Pride and Prejudice",
+        "author": "Jane Austen"
+      }
+    ]);
+
+    server.add_or_replace_multiple_documents(body);
+
+    // 3 - Get the first document and compare
+
+    let expected = json!({
+        "id": 1,
+        "title": "Le Petit Prince",
+        "author": "Exupéry"
+    });
+
+    let (response, status_code) = server.get_document(1);
+    assert_eq!(status_code, 200);
+
+    assert_json_eq!(response, expected, ordered: false);
+
+}