diff --git a/book/src/dev/zebra-dependencies-for-audit.md b/book/src/dev/zebra-dependencies-for-audit.md
index f33aba321b8..7655ff275de 100644
--- a/book/src/dev/zebra-dependencies-for-audit.md
+++ b/book/src/dev/zebra-dependencies-for-audit.md
@@ -63,7 +63,7 @@ The following consensus, security, and functional changes are in Zebra's develop
 
 The following list of dependencies is out of scope for the audit. 
 
-Please ignore the dependency versions in these tables, some of them are are outdated. All versions of these dependencies are out of scope.
+Please ignore the dependency versions in these tables, some of them are outdated. All versions of these dependencies are out of scope.
 
 The latest versions of Zebra's dependencies are in [`Cargo.lock`](https://github.com/ZcashFoundation/zebra/tree/audit-v1.0.0-rc.0/Cargo.lock), including transitive dependencies. They can be viewed using `cargo tree`.
 
diff --git a/tower-batch-control/src/worker.rs b/tower-batch-control/src/worker.rs
index f2266e67100..865a2f37009 100644
--- a/tower-batch-control/src/worker.rs
+++ b/tower-batch-control/src/worker.rs
@@ -323,7 +323,7 @@ where
         // We don't schedule any batches on an errored service
         self.pending_batch_timer = None;
 
-        // By closing the mpsc::Receiver, we know that that the run() loop will
+        // By closing the mpsc::Receiver, we know that the run() loop will
         // drain all pending requests. We just need to make sure that any
         // requests that we receive before we've exhausted the receiver receive
         // the error:
diff --git a/zebra-chain/src/history_tree/tests/vectors.rs b/zebra-chain/src/history_tree/tests/vectors.rs
index e65da99b676..e8aeeeb447d 100644
--- a/zebra-chain/src/history_tree/tests/vectors.rs
+++ b/zebra-chain/src/history_tree/tests/vectors.rs
@@ -55,7 +55,7 @@ fn push_and_prune_for_network_upgrade(
         assert_eq!(first_commitment, ChainHistoryActivationReserved);
     }
 
-    // Build initial history tree tree with only the first block
+    // Build initial history tree with only the first block
     let first_sapling_root =
         sapling::tree::Root::try_from(**sapling_roots.get(&height).expect("test vector exists"))?;
     let mut tree = NonEmptyHistoryTree::from_block(
diff --git a/zebra-chain/src/transaction/builder.rs b/zebra-chain/src/transaction/builder.rs
index 37397353aab..bcf1570d595 100644
--- a/zebra-chain/src/transaction/builder.rs
+++ b/zebra-chain/src/transaction/builder.rs
@@ -26,7 +26,7 @@ impl Transaction {
         // > (nActionsOrchard > 0 and enableSpendsOrchard = 1).
         //
         // > A coinbase transaction for a block at block height greater than 0 MUST have
-        // > a script that, as its first item, encodes the block height height as follows. ...
+        // > a script that, as its first item, encodes the block height as follows. ...
         // > let heightBytes be the signed little-endian representation of height,
         // > using the minimum nonzero number of bytes such that the most significant byte
         // > is < 0x80. The length of heightBytes MUST be in the range {1 .. 5}.
diff --git a/zebra-consensus/src/checkpoint.rs b/zebra-consensus/src/checkpoint.rs
index 36b3a76d57f..e9fc2b616cb 100644
--- a/zebra-consensus/src/checkpoint.rs
+++ b/zebra-consensus/src/checkpoint.rs
@@ -1059,7 +1059,7 @@ where
     #[instrument(name = "checkpoint", skip(self, block))]
     fn call(&mut self, block: Arc<Block>) -> Self::Future {
         // Reset the verifier back to the state tip if requested
-        // (e.g. due to an error when committing a block to to the state)
+        // (e.g. due to an error when committing a block to the state)
         if let Ok(tip) = self.reset_receiver.try_recv() {
             self.reset_progress(tip);
         }
diff --git a/zebra-rpc/src/queue.rs b/zebra-rpc/src/queue.rs
index 4504cd2070f..78c9fdd9033 100644
--- a/zebra-rpc/src/queue.rs
+++ b/zebra-rpc/src/queue.rs
@@ -211,7 +211,7 @@ impl Runner {
 
     /// Remove transactions that are expired according to number of blocks and current spacing between blocks.
     fn remove_expired(&mut self, spacing: Duration) {
-        // Have some extra time to to make sure we re-submit each transaction `NUMBER_OF_BLOCKS_TO_EXPIRE`
+        // Have some extra time to make sure we re-submit each transaction `NUMBER_OF_BLOCKS_TO_EXPIRE`
         // times, as the main loop also takes some time to run.
         let extra_time = Duration::seconds(5);