diff --git a/heed/src/db/polymorph.rs b/heed/src/db/polymorph.rs
index 5bb73c77..cc918bc8 100644
--- a/heed/src/db/polymorph.rs
+++ b/heed/src/db/polymorph.rs
@@ -158,7 +158,7 @@ impl PolyDatabase {
         KC: BytesEncode<'a>,
         DC: BytesDecode<'txn>,
     {
-        assert_matching_env_txn!(self, txn);
+        assert_eq_env_db_txn!(self, txn);
 
         let key_bytes: Cow<[u8]> = KC::bytes_encode(&key).map_err(Error::Encoding)?;
 
@@ -232,7 +232,7 @@ impl PolyDatabase {
         KC: BytesEncode<'a> + BytesDecode<'txn>,
         DC: BytesDecode<'txn>,
     {
-        assert_matching_env_txn!(self, txn);
+        assert_eq_env_db_txn!(self, txn);
 
         let mut cursor = RoCursor::new(txn, self.dbi)?;
         let key_bytes: Cow<[u8]> = KC::bytes_encode(&key).map_err(Error::Encoding)?;
@@ -300,7 +300,7 @@ impl PolyDatabase {
         KC: BytesEncode<'a> + BytesDecode<'txn>,
         DC: BytesDecode<'txn>,
     {
-        assert_matching_env_txn!(self, txn);
+        assert_eq_env_db_txn!(self, txn);
 
         let mut cursor = RoCursor::new(txn, self.dbi)?;
         let key_bytes: Cow<[u8]> = KC::bytes_encode(&key).map_err(Error::Encoding)?;
@@ -372,7 +372,7 @@ impl PolyDatabase {
         KC: BytesEncode<'a> + BytesDecode<'txn>,
         DC: BytesDecode<'txn>,
     {
-        assert_matching_env_txn!(self, txn);
+        assert_eq_env_db_txn!(self, txn);
 
         let mut cursor = RoCursor::new(txn, self.dbi)?;
         let key_bytes: Cow<[u8]> = KC::bytes_encode(&key).map_err(Error::Encoding)?;
@@ -443,7 +443,7 @@ impl PolyDatabase {
         KC: BytesEncode<'a> + BytesDecode<'txn>,
         DC: BytesDecode<'txn>,
     {
-        assert_matching_env_txn!(self, txn);
+        assert_eq_env_db_txn!(self, txn);
 
         let mut cursor = RoCursor::new(txn, self.dbi)?;
         let key_bytes: Cow<[u8]> = KC::bytes_encode(&key).map_err(Error::Encoding)?;
@@ -497,7 +497,7 @@ impl PolyDatabase {
         KC: BytesDecode<'txn>,
         DC: BytesDecode<'txn>,
     {
-        assert_matching_env_txn!(self, txn);
+        assert_eq_env_db_txn!(self, txn);
 
         let mut cursor = RoCursor::new(txn, self.dbi)?;
         match cursor.move_on_first() {
@@ -550,7 +550,7 @@ impl PolyDatabase {
         KC: BytesDecode<'txn>,
         DC: BytesDecode<'txn>,
     {
-        assert_matching_env_txn!(self, txn);
+        assert_eq_env_db_txn!(self, txn);
 
         let mut cursor = RoCursor::new(txn, self.dbi)?;
         match cursor.move_on_last() {
@@ -603,7 +603,7 @@ impl PolyDatabase {
     /// # Ok(()) }
     /// ```
     pub fn len<'txn>(&self, txn: &'txn RoTxn) -> Result<u64> {
-        assert_matching_env_txn!(self, txn);
+        assert_eq_env_db_txn!(self, txn);
 
         let mut db_stat = mem::MaybeUninit::uninit();
         let result = unsafe { mdb_result(ffi::mdb_stat(txn.txn, self.dbi, db_stat.as_mut_ptr())) };
@@ -656,7 +656,7 @@ impl PolyDatabase {
     /// # Ok(()) }
     /// ```
     pub fn is_empty<'txn>(&self, txn: &'txn RoTxn) -> Result<bool> {
-        assert_matching_env_txn!(self, txn);
+        assert_eq_env_db_txn!(self, txn);
 
         let mut cursor = RoCursor::new(txn, self.dbi)?;
         match cursor.move_on_first()? {
@@ -702,7 +702,7 @@ impl PolyDatabase {
     /// # Ok(()) }
     /// ```
     pub fn iter<'txn, KC, DC>(&self, txn: &'txn RoTxn) -> Result<RoIter<'txn, KC, DC>> {
-        assert_matching_env_txn!(self, txn);
+        assert_eq_env_db_txn!(self, txn);
 
         RoCursor::new(txn, self.dbi).map(|cursor| RoIter::new(cursor))
     }
@@ -757,7 +757,7 @@ impl PolyDatabase {
     /// # Ok(()) }
     /// ```
     pub fn iter_mut<'txn, KC, DC>(&self, txn: &'txn mut RwTxn) -> Result<RwIter<'txn, KC, DC>> {
-        assert_matching_env_txn!(self, txn);
+        assert_eq_env_db_txn!(self, txn);
 
         RwCursor::new(txn, self.dbi).map(|cursor| RwIter::new(cursor))
     }
@@ -799,7 +799,7 @@ impl PolyDatabase {
     /// # Ok(()) }
     /// ```
     pub fn rev_iter<'txn, KC, DC>(&self, txn: &'txn RoTxn) -> Result<RoRevIter<'txn, KC, DC>> {
-        assert_matching_env_txn!(self, txn);
+        assert_eq_env_db_txn!(self, txn);
 
         RoCursor::new(txn, self.dbi).map(|cursor| RoRevIter::new(cursor))
     }
@@ -858,7 +858,7 @@ impl PolyDatabase {
         &self,
         txn: &'txn mut RwTxn,
     ) -> Result<RwRevIter<'txn, KC, DC>> {
-        assert_matching_env_txn!(self, txn);
+        assert_eq_env_db_txn!(self, txn);
 
         RwCursor::new(txn, self.dbi).map(|cursor| RwRevIter::new(cursor))
     }
@@ -911,7 +911,7 @@ impl PolyDatabase {
         KC: BytesEncode<'a>,
         R: RangeBounds<KC::EItem>,
     {
-        assert_matching_env_txn!(self, txn);
+        assert_eq_env_db_txn!(self, txn);
 
         let start_bound = match range.start_bound() {
             Bound::Included(bound) => {
@@ -1002,7 +1002,7 @@ impl PolyDatabase {
         KC: BytesEncode<'a>,
         R: RangeBounds<KC::EItem>,
     {
-        assert_matching_env_txn!(self, txn);
+        assert_eq_env_db_txn!(self, txn);
 
         let start_bound = match range.start_bound() {
             Bound::Included(bound) => {
@@ -1080,7 +1080,7 @@ impl PolyDatabase {
         KC: BytesEncode<'a>,
         R: RangeBounds<KC::EItem>,
     {
-        assert_matching_env_txn!(self, txn);
+        assert_eq_env_db_txn!(self, txn);
 
         let start_bound = match range.start_bound() {
             Bound::Included(bound) => {
@@ -1171,7 +1171,7 @@ impl PolyDatabase {
         KC: BytesEncode<'a>,
         R: RangeBounds<KC::EItem>,
     {
-        assert_matching_env_txn!(self, txn);
+        assert_eq_env_db_txn!(self, txn);
 
         let start_bound = match range.start_bound() {
             Bound::Included(bound) => {
@@ -1249,7 +1249,7 @@ impl PolyDatabase {
     where
         KC: BytesEncode<'a>,
     {
-        assert_matching_env_txn!(self, txn);
+        assert_eq_env_db_txn!(self, txn);
 
         let prefix_bytes = KC::bytes_encode(prefix).map_err(Error::Encoding)?;
         let prefix_bytes = prefix_bytes.into_owned();
@@ -1318,7 +1318,7 @@ impl PolyDatabase {
     where
         KC: BytesEncode<'a>,
     {
-        assert_matching_env_txn!(self, txn);
+        assert_eq_env_db_txn!(self, txn);
 
         let prefix_bytes = KC::bytes_encode(prefix).map_err(Error::Encoding)?;
         let prefix_bytes = prefix_bytes.into_owned();
@@ -1374,7 +1374,7 @@ impl PolyDatabase {
     where
         KC: BytesEncode<'a>,
     {
-        assert_matching_env_txn!(self, txn);
+        assert_eq_env_db_txn!(self, txn);
 
         let prefix_bytes = KC::bytes_encode(prefix).map_err(Error::Encoding)?;
         let prefix_bytes = prefix_bytes.into_owned();
@@ -1443,7 +1443,7 @@ impl PolyDatabase {
     where
         KC: BytesEncode<'a>,
     {
-        assert_matching_env_txn!(self, txn);
+        assert_eq_env_db_txn!(self, txn);
 
         let prefix_bytes = KC::bytes_encode(prefix).map_err(Error::Encoding)?;
         let prefix_bytes = prefix_bytes.into_owned();
@@ -1493,7 +1493,7 @@ impl PolyDatabase {
         KC: BytesEncode<'a>,
         DC: BytesEncode<'a>,
     {
-        assert_matching_env_txn!(self, txn);
+        assert_eq_env_db_txn!(self, txn);
 
         let key_bytes: Cow<[u8]> = KC::bytes_encode(&key).map_err(Error::Encoding)?;
         let data_bytes: Cow<[u8]> = DC::bytes_encode(&data).map_err(Error::Encoding)?;
@@ -1554,7 +1554,7 @@ impl PolyDatabase {
         KC: BytesEncode<'a>,
         F: FnMut(&mut ReservedSpace) -> io::Result<()>,
     {
-        assert_matching_env_txn!(self, txn);
+        assert_eq_env_db_txn!(self, txn);
 
         let key_bytes: Cow<[u8]> = KC::bytes_encode(&key).map_err(Error::Encoding)?;
         let mut key_val = unsafe { crate::into_val(&key_bytes) };
@@ -1620,7 +1620,7 @@ impl PolyDatabase {
         KC: BytesEncode<'a>,
         DC: BytesEncode<'a>,
     {
-        assert_matching_env_txn!(self, txn);
+        assert_eq_env_db_txn!(self, txn);
 
         let key_bytes: Cow<[u8]> = KC::bytes_encode(&key).map_err(Error::Encoding)?;
         let data_bytes: Cow<[u8]> = DC::bytes_encode(&data).map_err(Error::Encoding)?;
@@ -1681,7 +1681,7 @@ impl PolyDatabase {
     where
         KC: BytesEncode<'a>,
     {
-        assert_matching_env_txn!(self, txn);
+        assert_eq_env_db_txn!(self, txn);
 
         let key_bytes: Cow<[u8]> = KC::bytes_encode(&key).map_err(Error::Encoding)?;
         let mut key_val = unsafe { crate::into_val(&key_bytes) };
@@ -1749,7 +1749,7 @@ impl PolyDatabase {
         KC: BytesEncode<'a> + BytesDecode<'txn>,
         R: RangeBounds<KC::EItem>,
     {
-        assert_matching_env_txn!(self, txn);
+        assert_eq_env_db_txn!(self, txn);
 
         let mut count = 0;
         let mut iter = self.range_mut::<KC, DecodeIgnore, _>(txn, range)?;
@@ -1806,7 +1806,7 @@ impl PolyDatabase {
     /// # Ok(()) }
     /// ```
     pub fn clear(&self, txn: &mut RwTxn) -> Result<()> {
-        assert_matching_env_txn!(self, txn);
+        assert_eq_env_db_txn!(self, txn);
 
         unsafe { mdb_result(ffi::mdb_drop(txn.txn.txn, self.dbi, 0)).map_err(Into::into) }
     }
diff --git a/heed/src/env.rs b/heed/src/env.rs
index dc5c20e0..91aacb1c 100644
--- a/heed/src/env.rs
+++ b/heed/src/env.rs
@@ -22,7 +22,9 @@ use synchronoise::event::SignalEvent;
 
 use crate::mdb::error::mdb_result;
 use crate::mdb::ffi;
-use crate::{Database, Error, Flags, PolyDatabase, Result, RoCursor, RoTxn, RwTxn};
+use crate::{
+    assert_eq_env_txn, Database, Error, Flags, PolyDatabase, Result, RoCursor, RoTxn, RwTxn,
+};
 
 /// The list of opened environments, the value is an optional environment, it is None
 /// when someone asks to close the environment, closing is a two-phase step, to make sure
@@ -297,7 +299,7 @@ impl Drop for EnvInner {
                 unsafe {
                     let _ = ffi::mdb_env_close(self.env);
                 }
-                // We signal to all the waiters that we have closed the env.
+                // We signal to all the waiters that the env is closed now.
                 signal_event.signal();
             }
         }
@@ -442,6 +444,8 @@ impl Env {
         KC: 'static,
         DC: 'static,
     {
+        assert_eq_env_txn!(self, rtxn);
+
         let types = (TypeId::of::<KC>(), TypeId::of::<DC>());
         match self.raw_init_database(rtxn.txn, name, Some(types), false) {
             Ok(dbi) => Ok(Some(Database::new(self.env_mut_ptr() as _, dbi))),
@@ -464,6 +468,8 @@ impl Env {
         rtxn: &RoTxn,
         name: Option<&str>,
     ) -> Result<Option<PolyDatabase>> {
+        assert_eq_env_txn!(self, rtxn);
+
         match self.raw_init_database(rtxn.txn, name, None, false) {
             Ok(dbi) => Ok(Some(PolyDatabase::new(self.env_mut_ptr() as _, dbi))),
             Err(Error::Mdb(e)) if e.not_found() => Ok(None),
@@ -489,6 +495,8 @@ impl Env {
         KC: 'static,
         DC: 'static,
     {
+        assert_eq_env_txn!(self, wtxn);
+
         let types = (TypeId::of::<KC>(), TypeId::of::<DC>());
         match self.raw_init_database(wtxn.txn.txn, name, Some(types), true) {
             Ok(dbi) => Ok(Database::new(self.env_mut_ptr() as _, dbi)),
@@ -510,6 +518,8 @@ impl Env {
         wtxn: &mut RwTxn,
         name: Option<&str>,
     ) -> Result<PolyDatabase> {
+        assert_eq_env_txn!(self, wtxn);
+
         match self.raw_init_database(wtxn.txn.txn, name, None, true) {
             Ok(dbi) => Ok(PolyDatabase::new(self.env_mut_ptr() as _, dbi)),
             Err(e) => Err(e),
diff --git a/heed/src/lib.rs b/heed/src/lib.rs
index cefb56f3..2609b641 100644
--- a/heed/src/lib.rs
+++ b/heed/src/lib.rs
@@ -146,7 +146,7 @@ mod tests {
     }
 }
 
-macro_rules! assert_matching_env_txn {
+macro_rules! assert_eq_env_db_txn {
     ($database:ident, $txn:ident) => {
         assert!(
             $database.env_ident == $txn.env_mut_ptr() as usize,
@@ -155,4 +155,13 @@ macro_rules! assert_matching_env_txn {
     };
 }
 
-pub(crate) use assert_matching_env_txn;
+macro_rules! assert_eq_env_txn {
+    ($env:ident, $txn:ident) => {
+        assert!(
+            $env.env_mut_ptr() == $txn.env_mut_ptr(),
+            "The environment doesn't match the transaction's environment"
+        );
+    };
+}
+
+pub(crate) use {assert_eq_env_db_txn, assert_eq_env_txn};