diff --git a/Cargo.lock b/Cargo.lock
index aa6f99b8a..d985635be 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -37,7 +37,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 [[package]]
 name = "assert-json-diff"
 version = "1.0.1"
-source = "git+https://github.com/qdequele/assert-json-diff#29bdf99315e510abb2824ccb9353b3a7a330cbc4"
+source = "git+https://github.com/qdequele/assert-json-diff#9012a0c8866d0f2db0ef9a6242e4a19d1e8c67e4"
 dependencies = [
  "serde 1.0.102 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_json 1.0.41 (registry+https://github.com/rust-lang/crates.io-index)",
diff --git a/meilisearch-http/src/routes/mod.rs b/meilisearch-http/src/routes/mod.rs
index 31be1cacf..93b7e1391 100644
--- a/meilisearch-http/src/routes/mod.rs
+++ b/meilisearch-http/src/routes/mod.rs
@@ -96,7 +96,7 @@ pub fn load_routes(app: &mut tide::Server<Data>) {
         .post(|ctx| into_response(setting::update_displayed(ctx)))
         .delete(|ctx| into_response(setting::delete_displayed(ctx)));
 
-    app.at("/indexes/:index/settings/index-new-field")
+    app.at("/indexes/:index/settings/accept-new-fields")
         .get(|ctx| into_response(setting::get_accept_new_fields(ctx)))
         .post(|ctx| into_response(setting::update_accept_new_fields(ctx)));
 
diff --git a/meilisearch-http/tests/common.rs b/meilisearch-http/tests/common.rs
index 3836d4d74..7acb1c8a2 100644
--- a/meilisearch-http/tests/common.rs
+++ b/meilisearch-http/tests/common.rs
@@ -58,7 +58,7 @@ impl Server {
             let response: Value = serde_json::from_slice(&buf).unwrap();
 
             if response["status"] == "processed" {
-                eprintln!("{:?}", response);
+                eprintln!("{:#?}", response);
                 return;
             }
             block_on(sleep(Duration::from_secs(1)));
diff --git a/meilisearch-http/tests/settings.rs b/meilisearch-http/tests/settings.rs
index ecd5e107a..2f9c7c43c 100644
--- a/meilisearch-http/tests/settings.rs
+++ b/meilisearch-http/tests/settings.rs
@@ -117,8 +117,8 @@ fn write_all_and_delete() {
           "vote_average",
           "popularity"
         ],
-        "stopWords": null,
-        "synonyms": null,
+        "stopWords": [],
+        "synonyms": {},
         "acceptNewFields": true,
     });
 
@@ -242,7 +242,7 @@ fn write_all_and_update() {
             "rank",
             "poster",
         ],
-        "stopWords": null,
+        "stopWords": [],
         "synonyms": {
             "wolverine": ["xmen", "logan"],
             "logan": ["wolverine", "xmen"],
diff --git a/meilisearch-http/tests/settings_accept_new_fields.rs b/meilisearch-http/tests/settings_accept_new_fields.rs
new file mode 100644
index 000000000..6157e7cb5
--- /dev/null
+++ b/meilisearch-http/tests/settings_accept_new_fields.rs
@@ -0,0 +1,290 @@
+use assert_json_diff::assert_json_eq;
+use serde_json::json;
+
+mod common;
+
+#[test]
+fn index_new_fields_default() {
+    let mut server = common::Server::with_uid("movies");
+    let body = json!({
+        "uid": "movies",
+        "identifier": "id",
+    });
+    server.create_index(body);
+
+    // 1 - Add a document
+
+    let body = json!([{
+        "id": 1,
+        "title": "I'm a legend",
+    }]);
+
+    server.add_or_replace_multiple_documents(body);
+
+    // 2 - Get the complete document
+
+    let expected = json!({
+        "id": 1,
+        "title": "I'm a legend",
+    });
+
+    let (response, status_code) = server.get_document(1);
+    assert_eq!(status_code, 200);
+    assert_json_eq!(response, expected);
+
+    // 3 - Add a document with more fields
+
+    let body = json!([{
+        "id": 2,
+        "title": "I'm not a legend",
+        "description": "A bad copy of the original movie I'm a lengend"
+    }]);
+
+    server.add_or_replace_multiple_documents(body);
+
+    // 4 - Get the complete document
+
+    let expected = json!({
+        "id": 2,
+        "title": "I'm not a legend",
+        "description": "A bad copy of the original movie I'm a lengend"
+    });
+
+    let (response, status_code) = server.get_document(2);
+    assert_eq!(status_code, 200);
+    assert_json_eq!(response, expected);
+}
+
+#[test]
+fn index_new_fields_true() {
+    let mut server = common::Server::with_uid("movies");
+    let body = json!({
+        "uid": "movies",
+        "identifier": "id",
+    });
+    server.create_index(body);
+
+    // 1 - Set indexNewFields = true
+
+    server.update_accept_new_fields(json!(true));
+
+    // 2 - Add a document
+
+    let body = json!([{
+        "id": 1,
+        "title": "I'm a legend",
+    }]);
+
+    server.add_or_replace_multiple_documents(body);
+
+    // 3 - Get the complete document
+
+    let expected = json!({
+        "id": 1,
+        "title": "I'm a legend",
+    });
+
+    let (response, status_code) = server.get_document(1);
+    assert_eq!(status_code, 200);
+    assert_json_eq!(response, expected);
+
+    // 4 - Add a document with more fields
+
+    let body = json!([{
+        "id": 2,
+        "title": "I'm not a legend",
+        "description": "A bad copy of the original movie I'm a lengend"
+    }]);
+
+    server.add_or_replace_multiple_documents(body);
+
+    // 5 - Get the complete document
+
+    let expected = json!({
+        "id": 2,
+        "title": "I'm not a legend",
+        "description": "A bad copy of the original movie I'm a lengend"
+    });
+
+    let (response, status_code) = server.get_document(2);
+    assert_eq!(status_code, 200);
+    assert_json_eq!(response, expected);
+}
+
+#[test]
+fn index_new_fields_false() {
+    let mut server = common::Server::with_uid("movies");
+    let body = json!({
+        "uid": "movies",
+        "identifier": "id",
+    });
+    server.create_index(body);
+
+    // 1 - Set indexNewFields = false
+
+    server.update_accept_new_fields(json!(false));
+
+    // 2 - Add a document
+
+    let body = json!([{
+        "id": 1,
+        "title": "I'm a legend",
+    }]);
+
+    server.add_or_replace_multiple_documents(body);
+
+    // 3 - Get the complete document
+
+    let expected = json!({
+        "id": 1,
+    });
+
+    let (response, status_code) = server.get_document(1);
+    assert_eq!(status_code, 200);
+    assert_json_eq!(response, expected);
+
+    // 4 - Add a document with more fields
+
+    let body = json!([{
+        "id": 2,
+        "title": "I'm not a legend",
+        "description": "A bad copy of the original movie I'm a lengend"
+    }]);
+
+    server.add_or_replace_multiple_documents(body);
+
+    // 5 - Get the complete document
+
+    let expected = json!({
+        "id": 2,
+    });
+
+    let (response, status_code) = server.get_document(2);
+    assert_eq!(status_code, 200);
+    assert_json_eq!(response, expected);
+}
+
+#[test]
+fn index_new_fields_true_then_false() {
+    let mut server = common::Server::with_uid("movies");
+    let body = json!({
+        "uid": "movies",
+        "identifier": "id",
+    });
+    server.create_index(body);
+
+    // 1 - Set indexNewFields = true
+
+    server.update_accept_new_fields(json!(true));
+
+    // 2 - Add a document
+
+    let body = json!([{
+        "id": 1,
+        "title": "I'm a legend",
+    }]);
+
+    server.add_or_replace_multiple_documents(body);
+
+    // 3 - Get the complete document
+
+    let expected = json!({
+        "id": 1,
+        "title": "I'm a legend",
+    });
+
+    let (response, status_code) = server.get_document(1);
+    assert_eq!(status_code, 200);
+    assert_json_eq!(response, expected);
+
+    // 4 - Set indexNewFields = false
+
+    server.update_accept_new_fields(json!(false));
+
+    // 5 - Add a document with more fields
+
+    let body = json!([{
+        "id": 2,
+        "title": "I'm not a legend",
+        "description": "A bad copy of the original movie I'm a lengend"
+    }]);
+
+    server.add_or_replace_multiple_documents(body);
+
+    // 6 - Get the complete document
+
+    let expected = json!({
+        "id": 2,
+        "title": "I'm not a legend",
+    });
+
+    let (response, status_code) = server.get_document(2);
+    assert_eq!(status_code, 200);
+    assert_json_eq!(response, expected);
+}
+
+#[test]
+fn index_new_fields_false_then_true() {
+    let mut server = common::Server::with_uid("movies");
+    let body = json!({
+        "uid": "movies",
+        "identifier": "id",
+    });
+    server.create_index(body);
+
+    // 1 - Set indexNewFields = false
+
+    server.update_accept_new_fields(json!(false));
+
+    // 2 - Add a document
+
+    let body = json!([{
+        "id": 1,
+        "title": "I'm a legend",
+    }]);
+
+    server.add_or_replace_multiple_documents(body);
+
+    // 3 - Get the complete document
+
+    let expected = json!({
+        "id": 1,
+    });
+
+    let (response, status_code) = server.get_document(1);
+    assert_eq!(status_code, 200);
+    assert_json_eq!(response, expected);
+
+    // 4 - Set indexNewFields = false
+
+    server.update_accept_new_fields(json!(true));
+
+    // 5 - Add a document with more fields
+
+    let body = json!([{
+        "id": 2,
+        "title": "I'm not a legend",
+        "description": "A bad copy of the original movie I'm a lengend"
+    }]);
+
+    server.add_or_replace_multiple_documents(body);
+
+    // 6 - Get the complete document
+
+    let expected = json!({
+        "id": 1,
+    });
+
+    let (response, status_code) = server.get_document(1);
+    assert_eq!(status_code, 200);
+    assert_json_eq!(response, expected);
+
+    let expected = json!({
+        "id": 2,
+        "description": "A bad copy of the original movie I'm a lengend"
+    });
+
+    let (response, status_code) = server.get_document(2);
+    assert_eq!(status_code, 200);
+    assert_json_eq!(response, expected);
+}