diff --git a/Cargo.lock b/Cargo.lock
index e707317f2..63c0ea192 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -344,6 +344,15 @@ dependencies = [
  "scopeguard",
 ]
 
+[[package]]
+name = "crossbeam-queue"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7c979cd6cfe72335896575c6b5688da489e420d36a27a0b9eb0c73db574b4a4b"
+dependencies = [
+ "crossbeam-utils 0.6.6",
+]
+
 [[package]]
 name = "crossbeam-queue"
 version = "0.2.2"
@@ -354,6 +363,16 @@ dependencies = [
  "crossbeam-utils 0.7.2",
 ]
 
+[[package]]
+name = "crossbeam-utils"
+version = "0.6.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "04973fa96e96579258a5091af6003abde64af786b860f18622b82e026cca60e6"
+dependencies = [
+ "cfg-if 0.1.10",
+ "lazy_static",
+]
+
 [[package]]
 name = "crossbeam-utils"
 version = "0.7.2"
@@ -689,9 +708,9 @@ dependencies = [
 
 [[package]]
 name = "heed"
-version = "0.9.0"
+version = "0.10.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1cbfcd936aa75c7cb1a8485dd2506ea0ae204e2131bf614d8aa4e5f4177455b1"
+checksum = "68e5fb45cfad5bc754aeeac84a1e963aed4b34e577e388524e0d8ed6b50fbab0"
 dependencies = [
  "byteorder",
  "heed-traits",
@@ -700,6 +719,7 @@ dependencies = [
  "lmdb-rkv-sys",
  "once_cell",
  "page_size",
+ "synchronoise",
  "url",
  "zerocopy",
 ]
@@ -1604,7 +1624,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e92e15d89083484e11353891f1af602cc661426deb9564c298b270c726973280"
 dependencies = [
  "crossbeam-deque",
- "crossbeam-queue",
+ "crossbeam-queue 0.2.2",
  "crossbeam-utils 0.7.2",
  "lazy_static",
  "num_cpus",
@@ -1925,6 +1945,15 @@ dependencies = [
  "syn",
 ]
 
+[[package]]
+name = "synchronoise"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d717ed0efc9d39ab3b642a096bc369a3e02a38a51c41845d7fe31bdad1d6eaeb"
+dependencies = [
+ "crossbeam-queue 0.1.2",
+]
+
 [[package]]
 name = "synstructure"
 version = "0.12.4"
diff --git a/Cargo.toml b/Cargo.toml
index 9d30a6c44..d4a67c623 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -14,7 +14,7 @@ flate2 = "1.0.17"
 fst = "0.4.4"
 fxhash = "0.2.1"
 grenad = { git = "https://github.com/Kerollmops/grenad.git", rev = "ce3517f" }
-heed = { version = "0.9.0", default-features = false, features = ["lmdb"] }
+heed = { version = "0.10.0", default-features = false, features = ["lmdb"] }
 human_format = "1.0.3"
 indexmap = { version = "1.6.0", features = ["serde-1"] }
 jemallocator = "0.3.2"
diff --git a/src/mdfs.rs b/src/mdfs.rs
index 746d4bd4d..3182fa96e 100644
--- a/src/mdfs.rs
+++ b/src/mdfs.rs
@@ -8,7 +8,7 @@ use crate::Index;
 /// A mana depth first search implementation.
 pub struct Mdfs<'a> {
     index: &'a Index,
-    rtxn: &'a heed::RoTxn,
+    rtxn: &'a heed::RoTxn<'a>,
     words: &'a [(HashMap<String, (u8, RoaringBitmap)>, RoaringBitmap)],
     union_cache: HashMap<(usize, u8), RoaringBitmap>,
     candidates: RoaringBitmap,
diff --git a/src/search.rs b/src/search.rs
index 98376bf7e..ae2b5d127 100644
--- a/src/search.rs
+++ b/src/search.rs
@@ -21,7 +21,7 @@ pub struct Search<'a> {
     query: Option<String>,
     offset: usize,
     limit: usize,
-    rtxn: &'a heed::RoTxn,
+    rtxn: &'a heed::RoTxn<'a>,
     index: &'a Index,
 }
 
diff --git a/src/subcommand/serve.rs b/src/subcommand/serve.rs
index bd88c3661..7081a2a00 100644
--- a/src/subcommand/serve.rs
+++ b/src/subcommand/serve.rs
@@ -292,7 +292,7 @@ pub fn run(opt: Opt) -> anyhow::Result<()> {
                 .len() as usize;
 
             // And the number of documents in the database.
-            let rtxn = index_cloned.clone().read_txn().unwrap();
+            let rtxn = index_cloned.read_txn().unwrap();
             let docs_count = index_cloned.clone().number_of_documents(&rtxn).unwrap() as usize;
 
             IndexTemplate { db_name: db_name_cloned.clone(), db_size, docs_count }
@@ -330,7 +330,7 @@ pub fn run(opt: Opt) -> anyhow::Result<()> {
                     .len() as usize;
 
                 // And the number of documents in the database.
-                let rtxn = index_cloned.clone().read_txn().unwrap();
+                let rtxn = index_cloned.read_txn().unwrap();
                 let docs_count = index_cloned.clone().number_of_documents(&rtxn).unwrap() as usize;
 
                 let template = UpdatesTemplate {
diff --git a/src/update/clear_documents.rs b/src/update/clear_documents.rs
index 4e68aac4c..ae739bd0b 100644
--- a/src/update/clear_documents.rs
+++ b/src/update/clear_documents.rs
@@ -2,12 +2,12 @@ use roaring::RoaringBitmap;
 use crate::Index;
 
 pub struct ClearDocuments<'t, 'u, 'i> {
-    wtxn: &'t mut heed::RwTxn<'u>,
+    wtxn: &'t mut heed::RwTxn<'i, 'u>,
     index: &'i Index,
 }
 
 impl<'t, 'u, 'i> ClearDocuments<'t, 'u, 'i> {
-    pub fn new(wtxn: &'t mut heed::RwTxn<'u>, index: &'i Index) -> ClearDocuments<'t, 'u, 'i> {
+    pub fn new(wtxn: &'t mut heed::RwTxn<'i, 'u>, index: &'i Index) -> ClearDocuments<'t, 'u, 'i> {
         ClearDocuments { wtxn, index }
     }
 
diff --git a/src/update/delete_documents.rs b/src/update/delete_documents.rs
index e9c3370de..1b29ab0d1 100644
--- a/src/update/delete_documents.rs
+++ b/src/update/delete_documents.rs
@@ -8,7 +8,7 @@ use crate::{Index, BEU32, SmallString32};
 use super::ClearDocuments;
 
 pub struct DeleteDocuments<'t, 'u, 'i> {
-    wtxn: &'t mut heed::RwTxn<'u>,
+    wtxn: &'t mut heed::RwTxn<'i, 'u>,
     index: &'i Index,
     users_ids_documents_ids: fst::Map<Vec<u8>>,
     documents_ids: RoaringBitmap,
@@ -16,7 +16,7 @@ pub struct DeleteDocuments<'t, 'u, 'i> {
 
 impl<'t, 'u, 'i> DeleteDocuments<'t, 'u, 'i> {
     pub fn new(
-        wtxn: &'t mut heed::RwTxn<'u>,
+        wtxn: &'t mut heed::RwTxn<'i, 'u>,
         index: &'i Index,
     ) -> anyhow::Result<DeleteDocuments<'t, 'u, 'i>>
     {
diff --git a/src/update/index_documents/mod.rs b/src/update/index_documents/mod.rs
index 2551a2f46..739d44f13 100644
--- a/src/update/index_documents/mod.rs
+++ b/src/update/index_documents/mod.rs
@@ -181,7 +181,7 @@ pub enum IndexDocumentsMethod {
 }
 
 pub struct IndexDocuments<'t, 'u, 'i> {
-    wtxn: &'t mut heed::RwTxn<'u>,
+    wtxn: &'t mut heed::RwTxn<'i, 'u>,
     index: &'i Index,
     log_every_n: Option<usize>,
     max_nb_chunks: Option<usize>,
@@ -195,7 +195,7 @@ pub struct IndexDocuments<'t, 'u, 'i> {
 }
 
 impl<'t, 'u, 'i> IndexDocuments<'t, 'u, 'i> {
-    pub fn new(wtxn: &'t mut heed::RwTxn<'u>, index: &'i Index) -> IndexDocuments<'t, 'u, 'i> {
+    pub fn new(wtxn: &'t mut heed::RwTxn<'i, 'u>, index: &'i Index) -> IndexDocuments<'t, 'u, 'i> {
         IndexDocuments {
             wtxn,
             index,
diff --git a/src/update/index_documents/transform.rs b/src/update/index_documents/transform.rs
index 1200d8403..0c9425ffb 100644
--- a/src/update/index_documents/transform.rs
+++ b/src/update/index_documents/transform.rs
@@ -23,7 +23,7 @@ pub struct TransformOutput {
 }
 
 pub struct Transform<'t, 'i> {
-    pub rtxn: &'t heed::RoTxn,
+    pub rtxn: &'t heed::RoTxn<'t>,
     pub index: &'i Index,
     pub chunk_compression_type: CompressionType,
     pub chunk_compression_level: Option<u32>,
diff --git a/src/update/update_builder.rs b/src/update/update_builder.rs
index 293930bbf..42c4f0754 100644
--- a/src/update/update_builder.rs
+++ b/src/update/update_builder.rs
@@ -72,7 +72,7 @@ impl UpdateBuilder {
 
     pub fn clear_documents<'t, 'u, 'i>(
         self,
-        wtxn: &'t mut heed::RwTxn<'u>,
+        wtxn: &'t mut heed::RwTxn<'i, 'u>,
         index: &'i Index,
     ) -> ClearDocuments<'t, 'u, 'i>
     {
@@ -81,7 +81,7 @@ impl UpdateBuilder {
 
     pub fn delete_documents<'t, 'u, 'i>(
         self,
-        wtxn: &'t mut heed::RwTxn<'u>,
+        wtxn: &'t mut heed::RwTxn<'i, 'u>,
         index: &'i Index,
     ) -> anyhow::Result<DeleteDocuments<'t, 'u, 'i>>
     {
@@ -90,7 +90,7 @@ impl UpdateBuilder {
 
     pub fn index_documents<'t, 'u, 'i>(
         self,
-        wtxn: &'t mut heed::RwTxn<'u>,
+        wtxn: &'t mut heed::RwTxn<'i, 'u>,
         index: &'i Index,
     ) -> IndexDocuments<'t, 'u, 'i>
     {