diff --git a/meilisearch-http/src/routes/setting.rs b/meilisearch-http/src/routes/setting.rs
index 3402cac1e..ecb97f233 100644
--- a/meilisearch-http/src/routes/setting.rs
+++ b/meilisearch-http/src/routes/setting.rs
@@ -115,7 +115,8 @@ pub async fn update_all(mut ctx: Request<Data>) -> SResult<Response> {
     };
 
     let mut writer = db.update_write_txn()?;
-    let update_id = index.settings_update(&mut writer, settings.into_update()?)?;
+    let settings = settings.into_update().map_err(ResponseError::bad_request)?;
+    let update_id = index.settings_update(&mut writer, settings)?;
     writer.commit()?;
 
     let response_body = IndexUpdateResponse { update_id };
@@ -177,7 +178,8 @@ pub async fn update_rules(mut ctx: Request<Data>) -> SResult<Response> {
     };
 
     let mut writer = db.update_write_txn()?;
-    let update_id = index.settings_update(&mut writer, settings.into_update()?)?;
+    let settings = settings.into_update().map_err(ResponseError::bad_request)?;
+    let update_id = index.settings_update(&mut writer, settings)?;
     writer.commit()?;
 
     let response_body = IndexUpdateResponse { update_id };
@@ -229,7 +231,8 @@ pub async fn update_distinct(mut ctx: Request<Data>) -> SResult<Response> {
     };
 
     let mut writer = db.update_write_txn()?;
-    let update_id = index.settings_update(&mut writer, settings.into_update()?)?;
+    let settings = settings.into_update().map_err(ResponseError::bad_request)?;
+    let update_id = index.settings_update(&mut writer, settings)?;
     writer.commit()?;
 
     let response_body = IndexUpdateResponse { update_id };
@@ -284,7 +287,8 @@ pub async fn update_searchable(mut ctx: Request<Data>) -> SResult<Response> {
     };
 
     let mut writer = db.update_write_txn()?;
-    let update_id = index.settings_update(&mut writer, settings.into_update()?)?;
+    let settings = settings.into_update().map_err(ResponseError::bad_request)?;
+    let update_id = index.settings_update(&mut writer, settings)?;
     writer.commit()?;
 
     let response_body = IndexUpdateResponse { update_id };
@@ -342,7 +346,8 @@ pub async fn update_displayed(mut ctx: Request<Data>) -> SResult<Response> {
     };
 
     let mut writer = db.update_write_txn()?;
-    let update_id = index.settings_update(&mut writer, settings.into_update()?)?;
+    let settings = settings.into_update().map_err(ResponseError::bad_request)?;
+    let update_id = index.settings_update(&mut writer, settings)?;
     writer.commit()?;
 
     let response_body = IndexUpdateResponse { update_id };
@@ -395,7 +400,8 @@ pub async fn update_accept_new_fields(mut ctx: Request<Data>) -> SResult<Respons
     };
 
     let mut writer = db.update_write_txn()?;
-    let update_id = index.settings_update(&mut writer, settings.into_update()?)?;
+    let settings = settings.into_update().map_err(ResponseError::bad_request)?;
+    let update_id = index.settings_update(&mut writer, settings)?;
     writer.commit()?;
 
     let response_body = IndexUpdateResponse { update_id };
diff --git a/meilisearch-http/tests/common.rs b/meilisearch-http/tests/common.rs
index 7acb1c8a2..95e59a1d3 100644
--- a/meilisearch-http/tests/common.rs
+++ b/meilisearch-http/tests/common.rs
@@ -260,6 +260,11 @@ impl Server {
         self.post_request_async(&url, body);
     }
 
+    pub fn update_ranking_rules_sync(&mut self, body: Value) -> (Value, StatusCode) {
+        let url = format!("/indexes/{}/settings/ranking-rules", self.uid);
+        self.post_request(&url, body)
+    }
+
     pub fn delete_ranking_rules(&mut self) -> (Value, StatusCode) {
         let url = format!("/indexes/{}/settings/ranking-rules", self.uid);
         self.delete_request_async(&url)
diff --git a/meilisearch-http/tests/settings_ranking_rules.rs b/meilisearch-http/tests/settings_ranking_rules.rs
index 39e4c7061..908dd9c31 100644
--- a/meilisearch-http/tests/settings_ranking_rules.rs
+++ b/meilisearch-http/tests/settings_ranking_rules.rs
@@ -37,7 +37,7 @@ fn write_all_and_delete() {
 
     let (response, _status_code) = server.get_ranking_rules();
 
-    let json = json!([
+    let expected = json!([
         "typo",
         "words",
         "proximity",
@@ -46,7 +46,7 @@ fn write_all_and_delete() {
         "exactness"
     ]);
 
-    assert_json_eq!(expect, response, ordered: false);
+    assert_json_eq!(expected, response, ordered: false);
 }
 
 #[test]
@@ -105,3 +105,37 @@ fn write_all_and_update() {
 
     assert_json_eq!(expected, response, ordered: false);
 }
+
+#[test]
+fn send_undefined_rule() {
+    let mut server = common::Server::with_uid("movies");
+    let body = json!({
+        "uid": "movies",
+        "identifier": "id",
+    });
+    server.create_index(body);
+
+    let body = json!([
+        "typos",
+    ]);
+
+    let (_response, status_code) = server.update_ranking_rules_sync(body);
+    assert_eq!(status_code, 400);
+}
+
+#[test]
+fn send_malformed_custom_rule() {
+    let mut server = common::Server::with_uid("movies");
+    let body = json!({
+        "uid": "movies",
+        "identifier": "id",
+    });
+    server.create_index(body);
+
+    let body = json!([
+        "dsc(truc)",
+    ]);
+
+    let (_response, status_code) = server.update_ranking_rules_sync(body);
+    assert_eq!(status_code, 400);
+}