diff --git a/milli/src/update/index_documents/merge_function.rs b/milli/src/update/index_documents/merge_function.rs
index 904368fb0..0a32603b5 100644
--- a/milli/src/update/index_documents/merge_function.rs
+++ b/milli/src/update/index_documents/merge_function.rs
@@ -18,10 +18,6 @@ pub fn fst_merge(_key: &[u8], values: &[Cow<[u8]>]) -> anyhow::Result<Vec<u8>> {
     Ok(build.into_inner().unwrap())
 }
 
-pub fn docid_word_positions_merge(key: &[u8], _values: &[Cow<[u8]>]) -> anyhow::Result<Vec<u8>> {
-    panic!("merging docid word positions is an error ({:?})", key.as_bstr())
-}
-
 pub fn keep_first(_key: &[u8], values: &[Cow<[u8]>]) -> anyhow::Result<Vec<u8>> {
     Ok(values.first().unwrap().to_vec())
 }
diff --git a/milli/src/update/index_documents/mod.rs b/milli/src/update/index_documents/mod.rs
index 7fb47fa4a..1d31cba85 100644
--- a/milli/src/update/index_documents/mod.rs
+++ b/milli/src/update/index_documents/mod.rs
@@ -25,8 +25,7 @@ use crate::update::{
 };
 use self::store::{Store, Readers};
 pub use self::merge_function::{
-    fst_merge, cbo_roaring_bitmap_merge, roaring_bitmap_merge,
-    docid_word_positions_merge, keep_first
+    fst_merge, cbo_roaring_bitmap_merge, roaring_bitmap_merge, keep_first
 };
 pub use self::transform::{Transform, TransformOutput};
 
@@ -619,12 +618,12 @@ impl<'t, 'u, 'i, 'a> IndexDocuments<'t, 'u, 'i, 'a> {
             total_databases,
         });
 
-        debug!("Writing the docid word positions into LMDB on disk...");
+        debug!("Inserting the docid word positions into LMDB on disk...");
         merge_into_lmdb_database(
             self.wtxn,
             *self.index.docid_word_positions.as_polymorph(),
             docid_word_positions_readers,
-            docid_word_positions_merge,
+            keep_first,
             write_method
         )?;