diff --git a/milli/src/update/index_documents/mod.rs b/milli/src/update/index_documents/mod.rs
index fe35e0143..b00dbf375 100644
--- a/milli/src/update/index_documents/mod.rs
+++ b/milli/src/update/index_documents/mod.rs
@@ -248,7 +248,7 @@ impl<'t, 'u, 'i, 'a> IndexDocuments<'t, 'u, 'i, 'a> {
             let chunk_iter = grenad_obkv_into_chunks(
                 documents_file,
                 params.clone(),
-                self.documents_chunk_size.unwrap_or(1024 * 1024 * 128), // 128MiB
+                self.documents_chunk_size.unwrap_or(1024 * 1024 * 4), // 4MiB
             );
 
             let result = chunk_iter.map(|chunk_iter| {