diff --git a/meilidb-data/src/database/documents_addition.rs b/meilidb-data/src/database/documents_addition.rs
index 15323be70..6e6c2003b 100644
--- a/meilidb-data/src/database/documents_addition.rs
+++ b/meilidb-data/src/database/documents_addition.rs
@@ -119,8 +119,9 @@ impl<'a> DocumentsAddition<'a> {
         main.set_ranked_map(&self.ranked_map)?;
 
         // update the "consistent" view of the Index
+        let words = Arc::new(words);
         let ranked_map = self.ranked_map;
-        let synonyms = fst::Set::from_bytes(lease_inner.synonyms.as_fst().to_vec()).unwrap(); // clone()
+        let synonyms = lease_inner.synonyms.clone();
         let schema = lease_inner.schema.clone();
         let raw = lease_inner.raw.clone();
         lease_inner.raw.compact();
diff --git a/meilidb-data/src/database/documents_deletion.rs b/meilidb-data/src/database/documents_deletion.rs
index 9813afe3c..d1413e353 100644
--- a/meilidb-data/src/database/documents_deletion.rs
+++ b/meilidb-data/src/database/documents_deletion.rs
@@ -118,8 +118,9 @@ impl<'a> DocumentsDeletion<'a> {
         main.set_ranked_map(&self.ranked_map)?;
 
         // update the "consistent" view of the Index
+        let words = Arc::new(words);
         let ranked_map = lease_inner.ranked_map.clone();
-        let synonyms = fst::Set::from_bytes(lease_inner.synonyms.as_fst().to_vec()).unwrap(); // clone()
+        let synonyms = lease_inner.synonyms.clone();
         let schema = lease_inner.schema.clone();
         let raw = lease_inner.raw.clone();
         lease_inner.raw.compact();
diff --git a/meilidb-data/src/database/index.rs b/meilidb-data/src/database/index.rs
index 886d31118..edec6a89b 100644
--- a/meilidb-data/src/database/index.rs
+++ b/meilidb-data/src/database/index.rs
@@ -30,8 +30,8 @@ pub struct IndexStats {
 pub struct Index(pub ArcSwap<InnerIndex>);
 
 pub struct InnerIndex {
-    pub words: fst::Set,
-    pub synonyms: fst::Set,
+    pub words: Arc<fst::Set>,
+    pub synonyms: Arc<fst::Set>,
     pub schema: Schema,
     pub ranked_map: RankedMap,
     pub raw: RawIndex, // TODO this will be a snapshot in the future
@@ -40,13 +40,13 @@ pub struct InnerIndex {
 impl Index {
     pub fn from_raw(raw: RawIndex) -> Result<Index, Error> {
         let words = match raw.main.words_set()? {
-            Some(words) => words,
-            None => fst::Set::default(),
+            Some(words) => Arc::new(words),
+            None => Arc::new(fst::Set::default()),
         };
 
         let synonyms = match raw.main.synonyms_set()? {
-            Some(synonyms) => synonyms,
-            None => fst::Set::default(),
+            Some(synonyms) => Arc::new(synonyms),
+            None => Arc::new(fst::Set::default()),
         };
 
         let schema = match raw.main.schema()? {
diff --git a/meilidb-data/src/database/synonyms_addition.rs b/meilidb-data/src/database/synonyms_addition.rs
index 563cb228f..e4c364387 100644
--- a/meilidb-data/src/database/synonyms_addition.rs
+++ b/meilidb-data/src/database/synonyms_addition.rs
@@ -72,8 +72,9 @@ impl<'a> SynonymsAddition<'a> {
         main.set_synonyms_set(&synonyms)?;
 
         // update the "consistent" view of the Index
-        let words = main.words_set()?.unwrap_or_default();
+        let words = Arc::new(main.words_set()?.unwrap_or_default());
         let ranked_map = lease_inner.ranked_map.clone();
+        let synonyms = Arc::new(synonyms);
         let schema = lease_inner.schema.clone();
         let raw = lease_inner.raw.clone();
         lease_inner.raw.compact();
diff --git a/meilidb-data/src/database/synonyms_deletion.rs b/meilidb-data/src/database/synonyms_deletion.rs
index c07e92859..6056dba3f 100644
--- a/meilidb-data/src/database/synonyms_deletion.rs
+++ b/meilidb-data/src/database/synonyms_deletion.rs
@@ -115,8 +115,9 @@ impl<'a> SynonymsDeletion<'a> {
         main.set_synonyms_set(&synonyms)?;
 
         // update the "consistent" view of the Index
-        let words = main.words_set()?.unwrap_or_default();
+        let words = Arc::new(main.words_set()?.unwrap_or_default());
         let ranked_map = lease_inner.ranked_map.clone();
+        let synonyms = Arc::new(synonyms);
         let schema = lease_inner.schema.clone();
         let raw = lease_inner.raw.clone();
         lease_inner.raw.compact();