diff --git a/crates/fuzzers/src/bin/fuzz-indexing.rs b/crates/fuzzers/src/bin/fuzz-indexing.rs
index e26303010..4df989b51 100644
--- a/crates/fuzzers/src/bin/fuzz-indexing.rs
+++ b/crates/fuzzers/src/bin/fuzz-indexing.rs
@@ -57,7 +57,8 @@ fn main() {
         let opt = opt.clone();
 
         let handle = std::thread::spawn(move || {
-            let mut options = EnvOpenOptions::new();
+            let options = EnvOpenOptions::new();
+            let mut options = options.read_txn_without_tls();
             options.map_size(1024 * 1024 * 1024 * 1024);
             let tempdir = match opt.path {
                 Some(path) => TempDir::new_in(path).unwrap(),
diff --git a/crates/index-scheduler/src/features.rs b/crates/index-scheduler/src/features.rs
index 394e6518f..bf78794ce 100644
--- a/crates/index-scheduler/src/features.rs
+++ b/crates/index-scheduler/src/features.rs
@@ -2,7 +2,7 @@ use std::sync::{Arc, RwLock};
 
 use meilisearch_types::features::{InstanceTogglableFeatures, Network, RuntimeTogglableFeatures};
 use meilisearch_types::heed::types::{SerdeJson, Str};
-use meilisearch_types::heed::{Database, Env, RwTxn};
+use meilisearch_types::heed::{Database, Env, RwTxn, WithoutTls};
 
 use crate::error::FeatureNotEnabledError;
 use crate::Result;
@@ -126,7 +126,7 @@ impl FeatureData {
     }
 
     pub fn new(
-        env: &Env,
+        env: &Env<WithoutTls>,
         wtxn: &mut RwTxn,
         instance_features: InstanceTogglableFeatures,
     ) -> Result<Self> {
diff --git a/crates/index-scheduler/src/index_mapper/index_map.rs b/crates/index-scheduler/src/index_mapper/index_map.rs
index e4eb9bfb8..acb95f249 100644
--- a/crates/index-scheduler/src/index_mapper/index_map.rs
+++ b/crates/index-scheduler/src/index_mapper/index_map.rs
@@ -304,7 +304,8 @@ fn create_or_open_index(
     map_size: usize,
     creation: bool,
 ) -> Result<Index> {
-    let mut options = EnvOpenOptions::new();
+    let options = EnvOpenOptions::new();
+    let mut options = options.read_txn_without_tls();
     options.map_size(clamp_to_page_size(map_size));
 
     // You can find more details about this experimental
@@ -333,7 +334,7 @@ fn create_or_open_index(
 #[cfg(test)]
 mod tests {
 
-    use meilisearch_types::heed::Env;
+    use meilisearch_types::heed::{Env, WithoutTls};
     use meilisearch_types::Index;
     use uuid::Uuid;
 
@@ -343,7 +344,7 @@ mod tests {
     use crate::IndexScheduler;
 
     impl IndexMapper {
-        fn test() -> (Self, Env, IndexSchedulerHandle) {
+        fn test() -> (Self, Env<WithoutTls>, IndexSchedulerHandle) {
             let (index_scheduler, handle) = IndexScheduler::test(true, vec![]);
             (index_scheduler.index_mapper, index_scheduler.env, handle)
         }
diff --git a/crates/index-scheduler/src/index_mapper/mod.rs b/crates/index-scheduler/src/index_mapper/mod.rs
index 32cfa94ad..c1f6ff472 100644
--- a/crates/index-scheduler/src/index_mapper/mod.rs
+++ b/crates/index-scheduler/src/index_mapper/mod.rs
@@ -4,7 +4,7 @@ use std::time::Duration;
 use std::{fs, thread};
 
 use meilisearch_types::heed::types::{SerdeJson, Str};
-use meilisearch_types::heed::{Database, Env, RoTxn, RwTxn};
+use meilisearch_types::heed::{Database, Env, RoTxn, RwTxn, WithoutTls};
 use meilisearch_types::milli;
 use meilisearch_types::milli::database_stats::DatabaseStats;
 use meilisearch_types::milli::update::IndexerConfig;
@@ -164,7 +164,7 @@ impl IndexMapper {
     }
 
     pub fn new(
-        env: &Env,
+        env: &Env<WithoutTls>,
         wtxn: &mut RwTxn,
         options: &IndexSchedulerOptions,
         budget: IndexBudget,
diff --git a/crates/index-scheduler/src/lib.rs b/crates/index-scheduler/src/lib.rs
index 3b61b5dc4..41c407494 100644
--- a/crates/index-scheduler/src/lib.rs
+++ b/crates/index-scheduler/src/lib.rs
@@ -54,7 +54,7 @@ use meilisearch_types::batches::Batch;
 use meilisearch_types::features::{InstanceTogglableFeatures, Network, RuntimeTogglableFeatures};
 use meilisearch_types::heed::byteorder::BE;
 use meilisearch_types::heed::types::I128;
-use meilisearch_types::heed::{self, Env, RoTxn};
+use meilisearch_types::heed::{self, Env, RoTxn, WithoutTls};
 use meilisearch_types::milli::index::IndexEmbeddingConfig;
 use meilisearch_types::milli::update::IndexerConfig;
 use meilisearch_types::milli::vector::{Embedder, EmbedderOptions, EmbeddingConfigs};
@@ -131,7 +131,7 @@ pub struct IndexSchedulerOptions {
 /// to be performed on them.
 pub struct IndexScheduler {
     /// The LMDB environment which the DBs are associated with.
-    pub(crate) env: Env,
+    pub(crate) env: Env<WithoutTls>,
 
     /// The list of tasks currently processing
     pub(crate) processing_tasks: Arc<RwLock<ProcessingTasks>>,
@@ -240,10 +240,9 @@ impl IndexScheduler {
         };
 
         let env = unsafe {
-            heed::EnvOpenOptions::new()
-                .max_dbs(Self::nb_db())
-                .map_size(budget.task_db_size)
-                .open(&options.tasks_path)
+            let options = heed::EnvOpenOptions::new();
+            let mut options = options.read_txn_without_tls();
+            options.max_dbs(Self::nb_db()).map_size(budget.task_db_size).open(&options.tasks_path)
         }?;
 
         // We **must** starts by upgrading the version because it'll also upgrade the required database before we can open them
@@ -358,7 +357,7 @@ impl IndexScheduler {
         }
     }
 
-    pub fn read_txn(&self) -> Result<RoTxn> {
+    pub fn read_txn(&self) -> Result<RoTxn<WithoutTls>> {
         self.env.read_txn().map_err(|e| e.into())
     }
 
@@ -427,12 +426,14 @@ impl IndexScheduler {
     /// If you need to fetch information from or perform an action on all indexes,
     /// see the `try_for_each_index` function.
     pub fn index(&self, name: &str) -> Result<Index> {
-        self.index_mapper.index(&self.env.read_txn()?, name)
+        let rtxn = self.env.read_txn()?;
+        self.index_mapper.index(&rtxn, name)
     }
 
     /// Return the boolean referring if index exists.
     pub fn index_exists(&self, name: &str) -> Result<bool> {
-        self.index_mapper.index_exists(&self.env.read_txn()?, name)
+        let rtxn = self.env.read_txn()?;
+        self.index_mapper.index_exists(&rtxn, name)
     }
 
     /// Return the name of all indexes without opening them.
@@ -507,7 +508,8 @@ impl IndexScheduler {
     /// 2. The name of the specific data related to the property can be `enqueued` for the `statuses`, `settingsUpdate` for the `types`, or the name of the index for the `indexes`, for example.
     /// 3. The number of times the properties appeared.
     pub fn get_stats(&self) -> Result<BTreeMap<String, BTreeMap<String, u64>>> {
-        self.queue.get_stats(&self.read_txn()?, &self.processing_tasks.read().unwrap())
+        let rtxn = self.read_txn()?;
+        self.queue.get_stats(&rtxn, &self.processing_tasks.read().unwrap())
     }
 
     // Return true if there is at least one task that is processing.
diff --git a/crates/index-scheduler/src/queue/batches.rs b/crates/index-scheduler/src/queue/batches.rs
index 970e41110..785d24931 100644
--- a/crates/index-scheduler/src/queue/batches.rs
+++ b/crates/index-scheduler/src/queue/batches.rs
@@ -3,7 +3,7 @@ use std::ops::{Bound, RangeBounds};
 
 use meilisearch_types::batches::{Batch, BatchId};
 use meilisearch_types::heed::types::{DecodeIgnore, SerdeBincode, SerdeJson, Str};
-use meilisearch_types::heed::{Database, Env, RoTxn, RwTxn};
+use meilisearch_types::heed::{Database, Env, RoTxn, RwTxn, WithoutTls};
 use meilisearch_types::milli::{CboRoaringBitmapCodec, RoaringBitmapCodec, BEU32};
 use meilisearch_types::tasks::{Kind, Status};
 use roaring::{MultiOps, RoaringBitmap};
@@ -66,7 +66,7 @@ impl BatchQueue {
         NUMBER_OF_DATABASES
     }
 
-    pub(super) fn new(env: &Env, wtxn: &mut RwTxn) -> Result<Self> {
+    pub(super) fn new(env: &Env<WithoutTls>, wtxn: &mut RwTxn) -> Result<Self> {
         Ok(Self {
             all_batches: env.create_database(wtxn, Some(db_name::ALL_BATCHES))?,
             status: env.create_database(wtxn, Some(db_name::BATCH_STATUS))?,
diff --git a/crates/index-scheduler/src/queue/mod.rs b/crates/index-scheduler/src/queue/mod.rs
index 8850eb8fa..b13e3ffe2 100644
--- a/crates/index-scheduler/src/queue/mod.rs
+++ b/crates/index-scheduler/src/queue/mod.rs
@@ -13,7 +13,7 @@ use std::time::Duration;
 
 use file_store::FileStore;
 use meilisearch_types::batches::BatchId;
-use meilisearch_types::heed::{Database, Env, RoTxn, RwTxn};
+use meilisearch_types::heed::{Database, Env, RoTxn, RwTxn, WithoutTls};
 use meilisearch_types::milli::{CboRoaringBitmapCodec, BEU32};
 use meilisearch_types::tasks::{Kind, KindWithContent, Status, Task};
 use roaring::RoaringBitmap;
@@ -157,7 +157,7 @@ impl Queue {
 
     /// Create an index scheduler and start its run loop.
     pub(crate) fn new(
-        env: &Env,
+        env: &Env<WithoutTls>,
         wtxn: &mut RwTxn,
         options: &IndexSchedulerOptions,
     ) -> Result<Self> {
diff --git a/crates/index-scheduler/src/queue/tasks.rs b/crates/index-scheduler/src/queue/tasks.rs
index 913ebcb30..afe510955 100644
--- a/crates/index-scheduler/src/queue/tasks.rs
+++ b/crates/index-scheduler/src/queue/tasks.rs
@@ -1,7 +1,7 @@
 use std::ops::{Bound, RangeBounds};
 
 use meilisearch_types::heed::types::{DecodeIgnore, SerdeBincode, SerdeJson, Str};
-use meilisearch_types::heed::{Database, Env, RoTxn, RwTxn};
+use meilisearch_types::heed::{Database, Env, RoTxn, RwTxn, WithoutTls};
 use meilisearch_types::milli::{CboRoaringBitmapCodec, RoaringBitmapCodec, BEU32};
 use meilisearch_types::tasks::{Kind, Status, Task};
 use roaring::{MultiOps, RoaringBitmap};
@@ -68,7 +68,7 @@ impl TaskQueue {
         NUMBER_OF_DATABASES
     }
 
-    pub(crate) fn new(env: &Env, wtxn: &mut RwTxn) -> Result<Self> {
+    pub(crate) fn new(env: &Env<WithoutTls>, wtxn: &mut RwTxn) -> Result<Self> {
         Ok(Self {
             all_tasks: env.create_database(wtxn, Some(db_name::ALL_TASKS))?,
             status: env.create_database(wtxn, Some(db_name::STATUS))?,
diff --git a/crates/index-scheduler/src/scheduler/process_snapshot_creation.rs b/crates/index-scheduler/src/scheduler/process_snapshot_creation.rs
index 3e1a63ce3..85522c160 100644
--- a/crates/index-scheduler/src/scheduler/process_snapshot_creation.rs
+++ b/crates/index-scheduler/src/scheduler/process_snapshot_creation.rs
@@ -28,7 +28,7 @@ impl IndexScheduler {
 
         // 2. Snapshot the index-scheduler LMDB env
         //
-        // When we call copy_to_file, LMDB opens a read transaction by itself,
+        // When we call copy_to_path, LMDB opens a read transaction by itself,
         // we can't provide our own. It is an issue as we would like to know
         // the update files to copy but new ones can be enqueued between the copy
         // of the env and the new transaction we open to retrieve the enqueued tasks.
@@ -42,7 +42,7 @@ impl IndexScheduler {
         progress.update_progress(SnapshotCreationProgress::SnapshotTheIndexScheduler);
         let dst = temp_snapshot_dir.path().join("tasks");
         fs::create_dir_all(&dst)?;
-        self.env.copy_to_file(dst.join("data.mdb"), CompactionOption::Enabled)?;
+        self.env.copy_to_path(dst.join("data.mdb"), CompactionOption::Enabled)?;
 
         // 2.2 Create a read transaction on the index-scheduler
         let rtxn = self.env.read_txn()?;
@@ -81,7 +81,7 @@ impl IndexScheduler {
             let dst = temp_snapshot_dir.path().join("indexes").join(uuid.to_string());
             fs::create_dir_all(&dst)?;
             index
-                .copy_to_file(dst.join("data.mdb"), CompactionOption::Enabled)
+                .copy_to_path(dst.join("data.mdb"), CompactionOption::Enabled)
                 .map_err(|e| Error::from_milli(e, Some(name.to_string())))?;
         }
 
@@ -98,7 +98,7 @@ impl IndexScheduler {
                 .max_dbs(2)
                 .open(&self.scheduler.auth_path)
         }?;
-        auth.copy_to_file(dst.join("data.mdb"), CompactionOption::Enabled)?;
+        auth.copy_to_path(dst.join("data.mdb"), CompactionOption::Enabled)?;
 
         // 5. Copy and tarball the flat snapshot
         progress.update_progress(SnapshotCreationProgress::CreateTheTarball);
diff --git a/crates/index-scheduler/src/upgrade/mod.rs b/crates/index-scheduler/src/upgrade/mod.rs
index 017685198..596d9a0c0 100644
--- a/crates/index-scheduler/src/upgrade/mod.rs
+++ b/crates/index-scheduler/src/upgrade/mod.rs
@@ -1,5 +1,5 @@
 use anyhow::bail;
-use meilisearch_types::heed::{Env, RwTxn};
+use meilisearch_types::heed::{Env, RwTxn, WithTls, WithoutTls};
 use meilisearch_types::tasks::{Details, KindWithContent, Status, Task};
 use meilisearch_types::versioning::{VERSION_MAJOR, VERSION_MINOR, VERSION_PATCH};
 use time::OffsetDateTime;
@@ -9,13 +9,17 @@ use crate::queue::TaskQueue;
 use crate::versioning::Versioning;
 
 trait UpgradeIndexScheduler {
-    fn upgrade(&self, env: &Env, wtxn: &mut RwTxn, original: (u32, u32, u32))
-        -> anyhow::Result<()>;
+    fn upgrade(
+        &self,
+        env: &Env<WithoutTls>,
+        wtxn: &mut RwTxn,
+        original: (u32, u32, u32),
+    ) -> anyhow::Result<()>;
     fn target_version(&self) -> (u32, u32, u32);
 }
 
 pub fn upgrade_index_scheduler(
-    env: &Env,
+    env: &Env<WithoutTls>,
     versioning: &Versioning,
     from: (u32, u32, u32),
     to: (u32, u32, u32),
@@ -91,7 +95,7 @@ struct ToCurrentNoOp {}
 impl UpgradeIndexScheduler for ToCurrentNoOp {
     fn upgrade(
         &self,
-        _env: &Env,
+        _env: &Env<WithoutTls>,
         _wtxn: &mut RwTxn,
         _original: (u32, u32, u32),
     ) -> anyhow::Result<()> {
diff --git a/crates/index-scheduler/src/versioning.rs b/crates/index-scheduler/src/versioning.rs
index 22132bf5f..107b8e0ba 100644
--- a/crates/index-scheduler/src/versioning.rs
+++ b/crates/index-scheduler/src/versioning.rs
@@ -1,5 +1,5 @@
 use meilisearch_types::heed::types::Str;
-use meilisearch_types::heed::{self, Database, Env, RoTxn, RwTxn};
+use meilisearch_types::heed::{self, Database, Env, RoTxn, RwTxn, WithoutTls};
 use meilisearch_types::milli::heed_codec::version::VersionCodec;
 use meilisearch_types::versioning;
 
@@ -46,12 +46,12 @@ impl Versioning {
     }
 
     /// Return `Self` without checking anything about the version
-    pub fn raw_new(env: &Env, wtxn: &mut RwTxn) -> Result<Self, heed::Error> {
+    pub fn raw_new(env: &Env<WithoutTls>, wtxn: &mut RwTxn) -> Result<Self, heed::Error> {
         let version = env.create_database(wtxn, Some(db_name::VERSION))?;
         Ok(Self { version })
     }
 
-    pub(crate) fn new(env: &Env, db_version: (u32, u32, u32)) -> Result<Self> {
+    pub(crate) fn new(env: &Env<WithoutTls>, db_version: (u32, u32, u32)) -> Result<Self> {
         let mut wtxn = env.write_txn()?;
         let this = Self::raw_new(env, &mut wtxn)?;
         let from = match this.get_version(&wtxn)? {
diff --git a/crates/meilisearch-auth/src/store.rs b/crates/meilisearch-auth/src/store.rs
index ef992e836..67059f854 100644
--- a/crates/meilisearch-auth/src/store.rs
+++ b/crates/meilisearch-auth/src/store.rs
@@ -9,7 +9,7 @@ use std::str::FromStr;
 use std::sync::Arc;
 
 use hmac::{Hmac, Mac};
-use meilisearch_types::heed::BoxedError;
+use meilisearch_types::heed::{BoxedError, WithTls};
 use meilisearch_types::index_uid_pattern::IndexUidPattern;
 use meilisearch_types::keys::KeyId;
 use meilisearch_types::milli;
@@ -31,7 +31,7 @@ const KEY_ID_ACTION_INDEX_EXPIRATION_DB_NAME: &str = "keyid-action-index-expirat
 
 #[derive(Clone)]
 pub struct HeedAuthStore {
-    env: Arc<Env>,
+    env: Arc<Env<WithTls>>,
     keys: Database<Bytes, SerdeJson<Key>>,
     action_keyid_index_expiration: Database<KeyIdActionCodec, SerdeJson<Option<OffsetDateTime>>>,
     should_close_on_drop: bool,
@@ -45,7 +45,7 @@ impl Drop for HeedAuthStore {
     }
 }
 
-pub fn open_auth_store_env(path: &Path) -> milli::heed::Result<milli::heed::Env> {
+pub fn open_auth_store_env(path: &Path) -> milli::heed::Result<milli::heed::Env<WithTls>> {
     let mut options = EnvOpenOptions::new();
     options.map_size(AUTH_STORE_SIZE); // 1GB
     options.max_dbs(2);
diff --git a/crates/meilisearch-types/src/error.rs b/crates/meilisearch-types/src/error.rs
index 5a0451b6c..6c060a42f 100644
--- a/crates/meilisearch-types/src/error.rs
+++ b/crates/meilisearch-types/src/error.rs
@@ -405,7 +405,7 @@ impl ErrorCode for milli::Error {
                 match error {
                     // TODO: wait for spec for new error codes.
                     UserError::SerdeJson(_)
-                    | UserError::InvalidLmdbOpenOptions
+                    | UserError::EnvAlreadyOpened
                     | UserError::DocumentLimitReached
                     | UserError::UnknownInternalDocumentId { .. } => Code::Internal,
                     UserError::InvalidStoreFile => Code::InvalidStoreFile,
@@ -501,8 +501,7 @@ impl ErrorCode for HeedError {
             HeedError::Mdb(_)
             | HeedError::Encoding(_)
             | HeedError::Decoding(_)
-            | HeedError::DatabaseClosing
-            | HeedError::BadOpenOptions { .. } => Code::Internal,
+            | HeedError::EnvAlreadyOpened => Code::Internal,
         }
     }
 }
diff --git a/crates/meilitool/src/main.rs b/crates/meilitool/src/main.rs
index 8a8b774b8..c32dadd5c 100644
--- a/crates/meilitool/src/main.rs
+++ b/crates/meilitool/src/main.rs
@@ -11,7 +11,7 @@ use meilisearch_auth::AuthController;
 use meilisearch_types::batches::Batch;
 use meilisearch_types::heed::types::{Bytes, SerdeJson, Str};
 use meilisearch_types::heed::{
-    CompactionOption, Database, Env, EnvOpenOptions, RoTxn, RwTxn, Unspecified,
+    CompactionOption, Database, Env, EnvOpenOptions, RoTxn, RwTxn, TlsUsage, Unspecified,
 };
 use meilisearch_types::milli::constants::RESERVED_VECTORS_FIELD_NAME;
 use meilisearch_types::milli::documents::{obkv_to_object, DocumentsBatchReader};
@@ -224,8 +224,8 @@ fn clear_task_queue(db_path: PathBuf) -> anyhow::Result<()> {
     Ok(())
 }
 
-fn try_opening_database<KC: 'static, DC: 'static>(
-    env: &Env,
+fn try_opening_database<KC: 'static, DC: 'static, T: TlsUsage>(
+    env: &Env<T>,
     rtxn: &RoTxn,
     db_name: &str,
 ) -> anyhow::Result<Database<KC, DC>> {
@@ -234,8 +234,8 @@ fn try_opening_database<KC: 'static, DC: 'static>(
         .with_context(|| format!("Missing the {db_name:?} database"))
 }
 
-fn try_opening_poly_database(
-    env: &Env,
+fn try_opening_poly_database<T: TlsUsage>(
+    env: &Env<T>,
     rtxn: &RoTxn,
     db_name: &str,
 ) -> anyhow::Result<Database<Unspecified, Unspecified>> {
@@ -386,9 +386,10 @@ fn export_a_dump(
     for result in index_mapping.iter(&rtxn)? {
         let (uid, uuid) = result?;
         let index_path = db_path.join("indexes").join(uuid.to_string());
-        let index = Index::new(EnvOpenOptions::new(), &index_path, false).with_context(|| {
-            format!("While trying to open the index at path {:?}", index_path.display())
-        })?;
+        let index = Index::new(EnvOpenOptions::new().read_txn_without_tls(), &index_path, false)
+            .with_context(|| {
+                format!("While trying to open the index at path {:?}", index_path.display())
+            })?;
 
         let rtxn = index.read_txn()?;
         let metadata = IndexMetadata {
@@ -456,9 +457,10 @@ fn compact_index(db_path: PathBuf, index_name: &str) -> anyhow::Result<()> {
         }
 
         let index_path = db_path.join("indexes").join(uuid.to_string());
-        let index = Index::new(EnvOpenOptions::new(), &index_path, false).with_context(|| {
-            format!("While trying to open the index at path {:?}", index_path.display())
-        })?;
+        let index = Index::new(EnvOpenOptions::new().read_txn_without_tls(), &index_path, false)
+            .with_context(|| {
+                format!("While trying to open the index at path {:?}", index_path.display())
+            })?;
 
         eprintln!("Awaiting for a mutable transaction...");
         let _wtxn = index.write_txn().context("While awaiting for a write transaction")?;
@@ -470,7 +472,7 @@ fn compact_index(db_path: PathBuf, index_name: &str) -> anyhow::Result<()> {
         eprintln!("Compacting the index...");
         let before_compaction = Instant::now();
         let new_file = index
-            .copy_to_file(&compacted_index_file_path, CompactionOption::Enabled)
+            .copy_to_path(&compacted_index_file_path, CompactionOption::Enabled)
             .with_context(|| format!("While compacting {}", compacted_index_file_path.display()))?;
 
         let after_size = new_file.metadata()?.len();
@@ -526,9 +528,10 @@ fn export_documents(
         if uid == index_name {
             let index_path = db_path.join("indexes").join(uuid.to_string());
             let index =
-                Index::new(EnvOpenOptions::new(), &index_path, false).with_context(|| {
-                    format!("While trying to open the index at path {:?}", index_path.display())
-                })?;
+                Index::new(EnvOpenOptions::new().read_txn_without_tls(), &index_path, false)
+                    .with_context(|| {
+                        format!("While trying to open the index at path {:?}", index_path.display())
+                    })?;
 
             let rtxn = index.read_txn()?;
             let fields_ids_map = index.fields_ids_map(&rtxn)?;
@@ -630,9 +633,10 @@ fn hair_dryer(
         if index_names.iter().any(|i| i == uid) {
             let index_path = db_path.join("indexes").join(uuid.to_string());
             let index =
-                Index::new(EnvOpenOptions::new(), &index_path, false).with_context(|| {
-                    format!("While trying to open the index at path {:?}", index_path.display())
-                })?;
+                Index::new(EnvOpenOptions::new().read_txn_without_tls(), &index_path, false)
+                    .with_context(|| {
+                        format!("While trying to open the index at path {:?}", index_path.display())
+                    })?;
 
             eprintln!("Trying to get a read transaction on the {uid} index...");
 
diff --git a/crates/meilitool/src/upgrade/v1_10.rs b/crates/meilitool/src/upgrade/v1_10.rs
index 043520e82..54fd01ac1 100644
--- a/crates/meilitool/src/upgrade/v1_10.rs
+++ b/crates/meilitool/src/upgrade/v1_10.rs
@@ -2,7 +2,7 @@ use std::path::Path;
 
 use anyhow::{bail, Context};
 use meilisearch_types::heed::types::{SerdeJson, Str};
-use meilisearch_types::heed::{Database, Env, EnvOpenOptions, RoTxn, RwTxn, Unspecified};
+use meilisearch_types::heed::{Database, Env, EnvOpenOptions, RoTxn, RwTxn, TlsUsage, Unspecified};
 use meilisearch_types::milli::index::{db_name, main_key};
 
 use super::v1_9;
@@ -90,9 +90,9 @@ fn update_index_stats(
     Ok(())
 }
 
-fn update_date_format(
+fn update_date_format<T: TlsUsage>(
     index_uid: &str,
-    index_env: &Env,
+    index_env: &Env<T>,
     index_wtxn: &mut RwTxn,
 ) -> anyhow::Result<()> {
     let main = try_opening_poly_database(index_env, index_wtxn, db_name::MAIN)
@@ -104,9 +104,9 @@ fn update_date_format(
     Ok(())
 }
 
-fn find_rest_embedders(
+fn find_rest_embedders<T: TlsUsage>(
     index_uid: &str,
-    index_env: &Env,
+    index_env: &Env<T>,
     index_txn: &RoTxn,
 ) -> anyhow::Result<Vec<String>> {
     let main = try_opening_poly_database(index_env, index_txn, db_name::MAIN)
diff --git a/crates/meilitool/src/upgrade/v1_12.rs b/crates/meilitool/src/upgrade/v1_12.rs
index 3ad171c31..54fbe0c8b 100644
--- a/crates/meilitool/src/upgrade/v1_12.rs
+++ b/crates/meilitool/src/upgrade/v1_12.rs
@@ -173,11 +173,12 @@ fn rebuild_field_distribution(db_path: &Path) -> anyhow::Result<()> {
 
             println!("\t- Rebuilding field distribution");
 
-            let index =
-                meilisearch_types::milli::Index::new(EnvOpenOptions::new(), &index_path, false)
-                    .with_context(|| {
-                        format!("while opening index {uid} at '{}'", index_path.display())
-                    })?;
+            let index = meilisearch_types::milli::Index::new(
+                EnvOpenOptions::new().read_txn_without_tls(),
+                &index_path,
+                false,
+            )
+            .with_context(|| format!("while opening index {uid} at '{}'", index_path.display()))?;
 
             let mut index_txn = index.write_txn()?;
 
diff --git a/crates/milli/src/index.rs b/crates/milli/src/index.rs
index 8c97ea39a..7e72dcecd 100644
--- a/crates/milli/src/index.rs
+++ b/crates/milli/src/index.rs
@@ -2,6 +2,7 @@ use std::borrow::Cow;
 use std::collections::{BTreeMap, BTreeSet, HashMap, HashSet};
 use std::convert::TryInto;
 use std::fs::File;
+use std::io::Seek;
 use std::path::Path;
 
 use heed::{types::*, WithoutTls};
@@ -339,8 +340,16 @@ impl Index {
         self.env.info().map_size
     }
 
-    pub fn copy_to_file<P: AsRef<Path>>(&self, path: P, option: CompactionOption) -> Result<File> {
-        self.env.copy_to_file(path, option).map_err(Into::into)
+    pub fn copy_to_file(&self, file: &mut File, option: CompactionOption) -> Result<()> {
+        self.env.copy_to_file(file, option).map_err(Into::into)
+    }
+
+    pub fn copy_to_path<P: AsRef<Path>>(&self, path: P, option: CompactionOption) -> Result<File> {
+        let mut file =
+            File::options().create(true).write(true).truncate(true).read(true).open(path)?;
+        self.copy_to_file(&mut file, option)?;
+        file.rewind()?;
+        Ok(file)
     }
 
     /// Returns an `EnvClosingEvent` that can be used to wait for the closing event,