diff --git a/milli/src/update/index_documents/mod.rs b/milli/src/update/index_documents/mod.rs
index 54d30f8fb..91d108c72 100644
--- a/milli/src/update/index_documents/mod.rs
+++ b/milli/src/update/index_documents/mod.rs
@@ -441,7 +441,11 @@ where
 
             let word_docids_iter = word_docids_builder.build().into_stream_merger_iter()?;
             // Run the word prefix docids update operation.
-            let mut builder = WordPrefixDocids::new(self.wtxn, self.index);
+            let mut builder = WordPrefixDocids::new(
+                self.wtxn,
+                self.index.word_docids.clone(),
+                self.index.word_prefix_docids.clone(),
+            );
             builder.chunk_compression_type = self.indexer_config.chunk_compression_type;
             builder.chunk_compression_level = self.indexer_config.chunk_compression_level;
             builder.max_nb_chunks = self.indexer_config.max_nb_chunks;
diff --git a/milli/src/update/word_prefix_docids.rs b/milli/src/update/word_prefix_docids.rs
index 4114f8baf..b166812a5 100644
--- a/milli/src/update/word_prefix_docids.rs
+++ b/milli/src/update/word_prefix_docids.rs
@@ -1,16 +1,18 @@
 use std::collections::{HashMap, HashSet};
 
 use grenad::CompressionType;
-use heed::types::ByteSlice;
+use heed::types::{ByteSlice, Str};
+use heed::Database;
 
 use crate::update::index_documents::{
     create_sorter, merge_roaring_bitmaps, sorter_into_lmdb_database, CursorClonableMmap, MergeFn,
 };
-use crate::{Index, Result};
+use crate::{Result, RoaringBitmapCodec};
 
 pub struct WordPrefixDocids<'t, 'u, 'i> {
     wtxn: &'t mut heed::RwTxn<'i, 'u>,
-    index: &'i Index,
+    word_docids: Database<Str, RoaringBitmapCodec>,
+    word_prefix_docids: Database<Str, RoaringBitmapCodec>,
     pub(crate) chunk_compression_type: CompressionType,
     pub(crate) chunk_compression_level: Option<u32>,
     pub(crate) max_nb_chunks: Option<usize>,
@@ -20,11 +22,13 @@ pub struct WordPrefixDocids<'t, 'u, 'i> {
 impl<'t, 'u, 'i> WordPrefixDocids<'t, 'u, 'i> {
     pub fn new(
         wtxn: &'t mut heed::RwTxn<'i, 'u>,
-        index: &'i Index,
+        word_docids: Database<Str, RoaringBitmapCodec>,
+        word_prefixes_docids: Database<Str, RoaringBitmapCodec>,
     ) -> WordPrefixDocids<'t, 'u, 'i> {
         WordPrefixDocids {
             wtxn,
-            index,
+            word_docids,
+            word_prefix_docids: word_prefixes_docids,
             chunk_compression_type: CompressionType::None,
             chunk_compression_level: None,
             max_nb_chunks: None,
@@ -83,7 +87,7 @@ impl<'t, 'u, 'i> WordPrefixDocids<'t, 'u, 'i> {
         }
 
         // We fetch the docids associated to the newly added word prefix fst only.
-        let db = self.index.word_docids.remap_data_type::<ByteSlice>();
+        let db = self.word_docids.remap_data_type::<ByteSlice>();
         for prefix in new_prefix_fst_words {
             let prefix = std::str::from_utf8(prefix.as_bytes())?;
             for result in db.prefix_iter(self.wtxn, prefix)? {
@@ -93,7 +97,7 @@ impl<'t, 'u, 'i> WordPrefixDocids<'t, 'u, 'i> {
         }
 
         // We remove all the entries that are no more required in this word prefix docids database.
-        let mut iter = self.index.word_prefix_docids.iter_mut(self.wtxn)?.lazily_decode_data();
+        let mut iter = self.word_prefix_docids.iter_mut(self.wtxn)?.lazily_decode_data();
         while let Some((prefix, _)) = iter.next().transpose()? {
             if del_prefix_fst_words.contains(prefix.as_bytes()) {
                 unsafe { iter.del_current()? };
@@ -105,7 +109,7 @@ impl<'t, 'u, 'i> WordPrefixDocids<'t, 'u, 'i> {
         // We finally write the word prefix docids into the LMDB database.
         sorter_into_lmdb_database(
             self.wtxn,
-            *self.index.word_prefix_docids.as_polymorph(),
+            *self.word_prefix_docids.as_polymorph(),
             prefix_docids_sorter,
             merge_roaring_bitmaps,
         )?;