diff --git a/heed/src/envs/env.rs b/heed/src/envs/env.rs
index 8180e617..51e6ffd1 100644
--- a/heed/src/envs/env.rs
+++ b/heed/src/envs/env.rs
@@ -537,6 +537,7 @@ impl Env<WithoutTls> {
     ///
     /// # Ok(()) }
     /// ```
+    #[cfg(not(master3))]
     pub fn nested_read_txn<'p>(&'p self, parent: &'p RwTxn) -> Result<RoTxn<'p, WithoutTls>> {
         RoTxn::<WithoutTls>::nested(self, parent)
     }