diff --git a/meilisearch-core/src/serde/convert_to_string.rs b/meilisearch-core/src/serde/convert_to_string.rs
index bac0de99e..4f89c6166 100644
--- a/meilisearch-core/src/serde/convert_to_string.rs
+++ b/meilisearch-core/src/serde/convert_to_string.rs
@@ -88,7 +88,7 @@ impl ser::Serializer for ConvertToString {
     }
 
     fn serialize_unit(self) -> Result<Self::Ok, Self::Error> {
-        Err(SerializerError::UnserializableType { type_name: "()" })
+        Ok("".to_string())
     }
 
     fn serialize_unit_struct(self, _name: &'static str) -> Result<Self::Ok, Self::Error> {