diff --git a/Cargo.lock b/Cargo.lock
index 5d87830a5..7df0e7e86 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -378,9 +378,7 @@ dependencies = [
 
 [[package]]
 name = "arroy"
-version = "0.2.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "efddeb1e7c32a551cc07ef4c3e181e3cd5478fdaf4f0bd799983171c1f6efe57"
+version = "0.3.0"
 dependencies = [
  "bytemuck",
  "byteorder",
@@ -1536,9 +1534,9 @@ checksum = "fea41bba32d969b513997752735605054bc0dfa92b4c56bf1189f2e174be7a10"
 
 [[package]]
 name = "doxygen-rs"
-version = "0.2.2"
+version = "0.4.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bff670ea0c9bbb8414e7efa6e23ebde2b8f520a7eef78273a3918cf1903e7505"
+checksum = "415b6ec780d34dcf624666747194393603d0373b7141eef01d12ee58881507d9"
 dependencies = [
  "phf",
 ]
@@ -2262,12 +2260,9 @@ checksum = "95505c38b4572b2d910cecb0281560f54b440a19336cbbcb27bf6ce6adc6f5a8"
 
 [[package]]
 name = "heed"
-version = "0.20.0-alpha.9"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9648a50991c86df7d00c56c268c27754fcf4c80be2ba57fc4a00dc928c6fe934"
+version = "0.20.0"
 dependencies = [
  "bitflags 2.5.0",
- "bytemuck",
  "byteorder",
  "heed-traits",
  "heed-types",
@@ -2281,15 +2276,11 @@ dependencies = [
 
 [[package]]
 name = "heed-traits"
-version = "0.20.0-alpha.9"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5ab0b7d9cde969ad36dde692e487dc89d97f7168bf6a7bd3b894ad4bf7278298"
+version = "0.20.0"
 
 [[package]]
 name = "heed-types"
-version = "0.20.0-alpha.9"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f0cb3567a7363f28b597bf6e9897b9466397951dd0e52df2c8196dd8a71af44a"
+version = "0.20.0"
 dependencies = [
  "bincode",
  "byteorder",
@@ -3189,14 +3180,11 @@ checksum = "f9d642685b028806386b2b6e75685faadd3eb65a85fff7df711ce18446a422da"
 
 [[package]]
 name = "lmdb-master-sys"
-version = "0.1.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "629c123f5321b48fa4f8f4d3b868165b748d9ba79c7103fb58e3a94f736bcedd"
+version = "0.2.0"
 dependencies = [
  "cc",
  "doxygen-rs",
  "libc",
- "pkg-config",
 ]
 
 [[package]]
diff --git a/index-scheduler/src/batch.rs b/index-scheduler/src/batch.rs
index bc9823a01..582497c15 100644
--- a/index-scheduler/src/batch.rs
+++ b/index-scheduler/src/batch.rs
@@ -785,10 +785,12 @@ impl IndexScheduler {
                 let dst = temp_snapshot_dir.path().join("auth");
                 fs::create_dir_all(&dst)?;
                 // TODO We can't use the open_auth_store_env function here but we should
-                let auth = milli::heed::EnvOpenOptions::new()
-                    .map_size(1024 * 1024 * 1024) // 1 GiB
-                    .max_dbs(2)
-                    .open(&self.auth_path)?;
+                let auth = unsafe {
+                    milli::heed::EnvOpenOptions::new()
+                        .map_size(1024 * 1024 * 1024) // 1 GiB
+                        .max_dbs(2)
+                        .open(&self.auth_path)
+                }?;
                 auth.copy_to_file(dst.join("data.mdb"), CompactionOption::Enabled)?;
 
                 // 5. Copy and tarball the flat snapshot
diff --git a/index-scheduler/src/lib.rs b/index-scheduler/src/lib.rs
index 5704f5354..dd2b296f6 100644
--- a/index-scheduler/src/lib.rs
+++ b/index-scheduler/src/lib.rs
@@ -453,10 +453,12 @@ impl IndexScheduler {
             )
         };
 
-        let env = heed::EnvOpenOptions::new()
-            .max_dbs(11)
-            .map_size(budget.task_db_size)
-            .open(options.tasks_path)?;
+        let env = unsafe {
+            heed::EnvOpenOptions::new()
+                .max_dbs(11)
+                .map_size(budget.task_db_size)
+                .open(options.tasks_path)
+        }?;
 
         let features = features::FeatureData::new(&env, options.instance_features)?;
 
@@ -585,9 +587,9 @@ impl IndexScheduler {
     }
 
     fn is_good_heed(tasks_path: &Path, map_size: usize) -> bool {
-        if let Ok(env) =
+        if let Ok(env) = unsafe {
             heed::EnvOpenOptions::new().map_size(clamp_to_page_size(map_size)).open(tasks_path)
-        {
+        } {
             env.prepare_for_closing().wait();
             true
         } else {
diff --git a/meilisearch-auth/src/store.rs b/meilisearch-auth/src/store.rs
index 1eebd3fe9..ef992e836 100644
--- a/meilisearch-auth/src/store.rs
+++ b/meilisearch-auth/src/store.rs
@@ -49,7 +49,7 @@ pub fn open_auth_store_env(path: &Path) -> milli::heed::Result<milli::heed::Env>
     let mut options = EnvOpenOptions::new();
     options.map_size(AUTH_STORE_SIZE); // 1GB
     options.max_dbs(2);
-    options.open(path)
+    unsafe { options.open(path) }
 }
 
 impl HeedAuthStore {
diff --git a/meilisearch-types/src/error.rs b/meilisearch-types/src/error.rs
index eea012331..158dfae92 100644
--- a/meilisearch-types/src/error.rs
+++ b/meilisearch-types/src/error.rs
@@ -423,7 +423,6 @@ impl ErrorCode for HeedError {
             HeedError::Mdb(_)
             | HeedError::Encoding(_)
             | HeedError::Decoding(_)
-            | HeedError::InvalidDatabaseTyping
             | HeedError::DatabaseClosing
             | HeedError::BadOpenOptions { .. } => Code::Internal,
         }
diff --git a/meilitool/src/main.rs b/meilitool/src/main.rs
index bfcbfdd6d..06c4890a5 100644
--- a/meilitool/src/main.rs
+++ b/meilitool/src/main.rs
@@ -80,9 +80,7 @@ fn main() -> anyhow::Result<()> {
 /// Clears the task queue located at `db_path`.
 fn clear_task_queue(db_path: PathBuf) -> anyhow::Result<()> {
     let path = db_path.join("tasks");
-    let env = EnvOpenOptions::new()
-        .max_dbs(100)
-        .open(&path)
+    let env = unsafe { EnvOpenOptions::new().max_dbs(100).open(&path) }
         .with_context(|| format!("While trying to open {:?}", path.display()))?;
 
     eprintln!("Deleting tasks from the database...");
@@ -193,9 +191,7 @@ fn export_a_dump(
         FileStore::new(db_path.join("update_files")).context("While opening the FileStore")?;
 
     let index_scheduler_path = db_path.join("tasks");
-    let env = EnvOpenOptions::new()
-        .max_dbs(100)
-        .open(&index_scheduler_path)
+    let env = unsafe { EnvOpenOptions::new().max_dbs(100).open(&index_scheduler_path) }
         .with_context(|| format!("While trying to open {:?}", index_scheduler_path.display()))?;
 
     eprintln!("Dumping the keys...");
diff --git a/milli/Cargo.toml b/milli/Cargo.toml
index 7d903178b..ab63a1fa7 100644
--- a/milli/Cargo.toml
+++ b/milli/Cargo.toml
@@ -30,7 +30,12 @@ grenad = { version = "0.4.6", default-features = false, features = [
     "rayon",
     "tempfile",
 ] }
-heed = { version = "0.20.0-alpha.9", default-features = false, features = [
+# heed = { version = "0.20.0", default-features = false, features = [
+#     "serde-json",
+#     "serde-bincode",
+#     "read-txn-no-tls",
+# ] }
+heed = { path = "../../heed/heed", default-features = false, features = [
     "serde-json",
     "serde-bincode",
     "read-txn-no-tls",
@@ -82,7 +87,8 @@ hf-hub = { git = "https://github.com/dureuill/hf-hub.git", branch = "rust_tls",
 ] }
 tiktoken-rs = "0.5.8"
 liquid = "0.26.4"
-arroy = "0.2.0"
+# arroy = "0.2.0"
+arroy = { path = "../../arroy" }
 rand = "0.8.5"
 tracing = "0.1.40"
 ureq = { version = "2.9.7", features = ["json"] }
diff --git a/milli/fuzz/.gitignore b/milli/fuzz/.gitignore
new file mode 100644
index 000000000..a0925114d
--- /dev/null
+++ b/milli/fuzz/.gitignore
@@ -0,0 +1,3 @@
+target
+corpus
+artifacts
diff --git a/milli/src/error.rs b/milli/src/error.rs
index 009781fcf..6db0dcac1 100644
--- a/milli/src/error.rs
+++ b/milli/src/error.rs
@@ -48,8 +48,6 @@ pub enum InternalError {
     GrenadInvalidFormatVersion,
     #[error("Invalid merge while processing {process}")]
     IndexingMergingKeys { process: &'static str },
-    #[error("{}", HeedError::InvalidDatabaseTyping)]
-    InvalidDatabaseTyping,
     #[error(transparent)]
     RayonThreadPool(#[from] ThreadPoolBuildError),
     #[error(transparent)]
@@ -429,7 +427,6 @@ impl From<HeedError> for Error {
             // TODO use the encoding
             HeedError::Encoding(_) => InternalError(Serialization(Encoding { db_name: None })),
             HeedError::Decoding(_) => InternalError(Serialization(Decoding { db_name: None })),
-            HeedError::InvalidDatabaseTyping => InternalError(InvalidDatabaseTyping),
             HeedError::DatabaseClosing => InternalError(DatabaseClosing),
             HeedError::BadOpenOptions { .. } => UserError(InvalidLmdbOpenOptions),
         }
diff --git a/milli/src/index.rs b/milli/src/index.rs
index 42b9cb111..739a7f202 100644
--- a/milli/src/index.rs
+++ b/milli/src/index.rs
@@ -184,7 +184,7 @@ impl Index {
 
         options.max_dbs(25);
 
-        let env = options.open(path)?;
+        let env = unsafe { options.open(path) }?;
         let mut wtxn = env.write_txn()?;
         let main = env.database_options().name(MAIN).create(&mut wtxn)?;
         let word_docids = env.create_database(&mut wtxn, Some(WORD_DOCIDS))?;
@@ -294,6 +294,11 @@ impl Index {
         self.env.read_txn()
     }
 
+    /// Create a static read transaction to be able to read the index without keeping a reference to it.
+    pub fn static_read_txn(&self) -> heed::Result<RoTxn<'static>> {
+        self.env.clone().static_read_txn()
+    }
+
     /// Returns the canonicalized path where the heed `Env` of this `Index` lives.
     pub fn path(&self) -> &Path {
         self.env.path()
diff --git a/milli/src/update/facet/mod.rs b/milli/src/update/facet/mod.rs
index 0af64c4c5..42994551f 100644
--- a/milli/src/update/facet/mod.rs
+++ b/milli/src/update/facet/mod.rs
@@ -379,7 +379,7 @@ pub(crate) mod test_helpers {
             let mut options = heed::EnvOpenOptions::new();
             let options = options.map_size(4096 * 4 * 1000 * 100);
             let tempdir = tempfile::TempDir::new().unwrap();
-            let env = options.open(tempdir.path()).unwrap();
+            let env = unsafe { options.open(tempdir.path()) }.unwrap();
             let mut wtxn = env.write_txn().unwrap();
             let content = env.create_database(&mut wtxn, None).unwrap();
             wtxn.commit().unwrap();
diff --git a/milli/src/update/index_documents/mod.rs b/milli/src/update/index_documents/mod.rs
index 936ce1efc..4d2fac7cb 100644
--- a/milli/src/update/index_documents/mod.rs
+++ b/milli/src/update/index_documents/mod.rs
@@ -556,7 +556,7 @@ where
                 let writer_index = (embedder_index as u16) << 8;
                 for k in 0..=u8::MAX {
                     let writer =
-                        arroy::Writer::new(vector_arroy, writer_index | (k as u16), dimension)?;
+                        arroy::Writer::new(vector_arroy, writer_index | (k as u16), dimension);
                     if writer.is_empty(wtxn)? {
                         break;
                     }
diff --git a/milli/src/update/index_documents/typed_chunk.rs b/milli/src/update/index_documents/typed_chunk.rs
index 6aad290e5..e0de2d5a1 100644
--- a/milli/src/update/index_documents/typed_chunk.rs
+++ b/milli/src/update/index_documents/typed_chunk.rs
@@ -661,7 +661,7 @@ pub(crate) fn write_typed_chunk_into_index(
             )?;
             let writer_index = (embedder_index as u16) << 8;
             // FIXME: allow customizing distance
-            let writers: std::result::Result<Vec<_>, _> = (0..=u8::MAX)
+            let writers: Vec<_> = (0..=u8::MAX)
                 .map(|k| {
                     arroy::Writer::new(
                         index.vector_arroy,
@@ -670,7 +670,6 @@ pub(crate) fn write_typed_chunk_into_index(
                     )
                 })
                 .collect();
-            let writers = writers?;
 
             // remove vectors for docids we want them removed
             let merger = remove_vectors_builder.build();