diff --git a/milli/src/update/del_add.rs b/milli/src/update/del_add.rs
index dc7c0409a..07a20b025 100644
--- a/milli/src/update/del_add.rs
+++ b/milli/src/update/del_add.rs
@@ -53,7 +53,9 @@ pub fn into_del_add_obkv<K: obkv::Key + PartialOrd>(
             value_writer.insert(DelAdd::Addition, value)?;
         }
         value_writer.finish()?;
-        writer.insert(key, &value_buffer)?;
+        if !value_buffer.is_empty() {
+            writer.insert(key, &value_buffer)?;
+        }
     }
 
     writer.finish()
diff --git a/milli/src/update/index_documents/extract/extract_word_position_docids.rs b/milli/src/update/index_documents/extract/extract_word_position_docids.rs
index 1b9ec66ff..89b77d140 100644
--- a/milli/src/update/index_documents/extract/extract_word_position_docids.rs
+++ b/milli/src/update/index_documents/extract/extract_word_position_docids.rs
@@ -121,6 +121,7 @@ fn words_position_into_sorter(
                 key
             }
             Both(key, _) => {
+                // both values needs to be kept because it will be used in other extractors.
                 value_writer.insert(DelAdd::Deletion, document_id.to_ne_bytes()).unwrap();
                 value_writer.insert(DelAdd::Addition, document_id.to_ne_bytes()).unwrap();
                 key