diff --git a/tokenizers/benches/bpe_benchmark.rs b/tokenizers/benches/bpe_benchmark.rs
index e20b3f33..270374fd 100644
--- a/tokenizers/benches/bpe_benchmark.rs
+++ b/tokenizers/benches/bpe_benchmark.rs
@@ -11,27 +11,28 @@ use tokenizers::normalizers::NormalizerWrapper;
 use tokenizers::pre_tokenizers::byte_level::ByteLevel;
 use tokenizers::pre_tokenizers::whitespace::Whitespace;
 use tokenizers::tokenizer::{AddedToken, EncodeInput, Tokenizer, Trainer};
-use tokenizers::{Model, Normalizer};
+use tokenizers::{Model, Normalizer, PreTokenizer};
 
 static BATCH_SIZE: usize = 1_000;
 
-fn create_gpt2_tokenizer(bpe: BPE) -> Tokenizer<BPE, NormalizerWrapper> {
+fn create_gpt2_tokenizer(bpe: BPE) -> Tokenizer<BPE, NormalizerWrapper, ByteLevel> {
     let mut tokenizer = Tokenizer::new(bpe);
-    tokenizer.with_pre_tokenizer(Box::new(ByteLevel::default()));
+    tokenizer.with_pre_tokenizer(ByteLevel::default());
     tokenizer.with_decoder(Box::new(ByteLevel::default()));
     tokenizer.add_tokens(&[AddedToken::from("ing", false).single_word(false)]);
     tokenizer.add_special_tokens(&[AddedToken::from("[ENT]", true).single_word(true)]);
     tokenizer
 }
 
-fn iter_bench_encode<M, N>(
+fn iter_bench_encode<M, N, PT>(
     iters: u64,
-    tokenizer: &Tokenizer<M, N>,
+    tokenizer: &Tokenizer<M, N, PT>,
     lines: &[EncodeInput],
 ) -> Duration
 where
     M: Model,
     N: Normalizer,
+    PT: PreTokenizer,
 {
     let mut duration = Duration::new(0, 0);
     let mut line_index: usize = 0;
@@ -47,14 +48,15 @@ where
     duration
 }
 
-fn iter_bench_encode_batch<M, N>(
+fn iter_bench_encode_batch<M, N, PT>(
     iters: u64,
-    tokenizer: &Tokenizer<M, N>,
+    tokenizer: &Tokenizer<M, N, PT>,
     batches: &[Vec<EncodeInput>],
 ) -> Duration
 where
     M: Model,
     N: Normalizer,
+    PT: PreTokenizer,
 {
     let mut duration = Duration::new(0, 0);
     let mut batch_index: usize = 0;
@@ -109,12 +111,17 @@ fn bench_gpt2(c: &mut Criterion) {
     });
 }
 
-fn iter_bench_train<T: Trainer<Model = BPE>>(
+fn iter_bench_train<T, M, PT>(
     iters: u64,
-    mut tokenizer: Tokenizer<BPE, NormalizerWrapper>,
+    mut tokenizer: Tokenizer<M, NormalizerWrapper, PT>,
     trainer: &T,
     files: Vec<String>,
-) -> Duration {
+) -> Duration
+where
+    M: Model,
+    PT: PreTokenizer,
+    T: Trainer<Model = M>,
+{
     let mut duration = Duration::new(0, 0);
     for _i in 0..iters {
         let start = Instant::now();
@@ -129,7 +136,7 @@ fn bench_train(c: &mut Criterion) {
     c.bench_function("BPE Train vocabulary (small)", |b| {
         b.iter_custom(|iters| {
             let mut tokenizer = Tokenizer::new(BPE::default());
-            tokenizer.with_pre_tokenizer(Box::new(Whitespace::default()));
+            tokenizer.with_pre_tokenizer(Whitespace::default());
             iter_bench_train(
                 iters,
                 tokenizer,
@@ -142,7 +149,7 @@ fn bench_train(c: &mut Criterion) {
     c.bench_function("BPE Train vocabulary (big)", |b| {
         b.iter_custom(|iters| {
             let mut tokenizer = Tokenizer::new(BPE::default());
-            tokenizer.with_pre_tokenizer(Box::new(Whitespace::default()));
+            tokenizer.with_pre_tokenizer(Whitespace::default());
             iter_bench_train(iters, tokenizer, &trainer, vec!["data/big.txt".to_string()])
         })
     });
diff --git a/tokenizers/src/cli.rs b/tokenizers/src/cli.rs
index 155b6f61..c1f09902 100644
--- a/tokenizers/src/cli.rs
+++ b/tokenizers/src/cli.rs
@@ -18,8 +18,8 @@ fn shell(matches: &ArgMatches) -> Result<()> {
         .expect("Must give a merges.txt file");
 
     let bpe = BPE::from_files(vocab, merges).build()?;
-    let mut tokenizer = Tokenizer::<_, NormalizerWrapper>::new(bpe);
-    tokenizer.with_pre_tokenizer(Box::new(ByteLevel::default()));
+    let mut tokenizer = Tokenizer::<_, NormalizerWrapper, ByteLevel>::new(bpe);
+    tokenizer.with_pre_tokenizer(ByteLevel::default());
     tokenizer.with_decoder(Box::new(ByteLevel::default()));
 
     tokenizer.add_tokens(&[AddedToken::from(String::from("ing"), false).single_word(false)]);
diff --git a/tokenizers/src/lib.rs b/tokenizers/src/lib.rs
index 833dad58..7e46af46 100644
--- a/tokenizers/src/lib.rs
+++ b/tokenizers/src/lib.rs
@@ -28,6 +28,7 @@
 //! use tokenizers::tokenizer::{Result, Tokenizer, EncodeInput};
 //! use tokenizers::models::bpe::BPE;
 //! use tokenizers::normalizers::NormalizerWrapper;
+//! use tokenizers::pre_tokenizers::PreTokenizerWrapper;
 //!
 //! fn main() -> Result<()> {
 //! let bpe_builder = BPE::from_files("./path/to/vocab.json", "./path/to/merges.txt");
@@ -36,7 +37,7 @@
 //!         .unk_token("[UNK]".into())
 //!         .build()?;
 //!
-//!     let mut tokenizer = Tokenizer::<_, NormalizerWrapper>::new(bpe);
+//!     let mut tokenizer = Tokenizer::<_, NormalizerWrapper, PreTokenizerWrapper>::new(bpe);
 //!
 //!     let encoding = tokenizer.encode("Hey there!", false)?;
 //!     println!("{:?}", encoding.get_tokens());
diff --git a/tokenizers/src/tokenizer/mod.rs b/tokenizers/src/tokenizer/mod.rs
index 3f94cab2..3545b532 100644
--- a/tokenizers/src/tokenizer/mod.rs
+++ b/tokenizers/src/tokenizer/mod.rs
@@ -213,10 +213,10 @@ impl fmt::Display for BuilderError {
 /// Builder for Tokenizer structs.
 ///
 /// `build()` fails if the `model` is missing.
-pub struct TokenizerBuilder<M, N> {
+pub struct TokenizerBuilder<M, N, PT> {
     model: Option<M>,
     normalizer: Option<N>,
-    pre_tokenizer: Option<Box<dyn PreTokenizer>>,
+    pre_tokenizer: Option<PT>,
     post_processor: Option<Box<dyn PostProcessor>>,
     decoder: Option<Box<dyn Decoder>>,
 
@@ -226,20 +226,22 @@ pub struct TokenizerBuilder<M, N> {
     padding: Option<PaddingParams>,
 }
 
-impl<M, N> Default for TokenizerBuilder<M, N>
+impl<M, N, PT> Default for TokenizerBuilder<M, N, PT>
 where
     M: Model,
     N: Normalizer,
+    PT: PreTokenizer,
 {
     fn default() -> Self {
         Self::new()
     }
 }
 
-impl<M, N> TokenizerBuilder<M, N>
+impl<M, N, PT> TokenizerBuilder<M, N, PT>
 where
     M: Model,
     N: Normalizer,
+    PT: PreTokenizer,
 {
     /// Get an empty TokenizerBuilder.
     pub fn new() -> Self {
@@ -258,7 +260,7 @@ where
     /// Convert the TokenizerBuilder to a Tokenizer.
     ///
     /// Conversion fails if the `model` is missing.
-    pub fn build(self) -> Result<Tokenizer<M, N>> {
+    pub fn build(self) -> Result<Tokenizer<M, N, PT>> {
         let model = self
             .model
             .ok_or_else(|| Box::new(BuilderError("Model missing.".into())))?;
@@ -288,7 +290,7 @@ where
     }
 
     /// Set the pretokenizer.
-    pub fn with_pretokenizer(mut self, pretokenizer: Option<Box<dyn PreTokenizer>>) -> Self {
+    pub fn with_pretokenizer(mut self, pretokenizer: Option<PT>) -> Self {
         self.pre_tokenizer = pretokenizer;
         self
     }
@@ -319,10 +321,10 @@ where
 }
 
 /// A `Tokenizer` is capable of encoding/decoding any text.
-pub struct Tokenizer<M, N> {
+pub struct Tokenizer<M, N, PT> {
     // Tokenizer parts
     normalizer: Option<N>,
-    pre_tokenizer: Option<Box<dyn PreTokenizer>>,
+    pre_tokenizer: Option<PT>,
     model: M,
     post_processor: Option<Box<dyn PostProcessor>>,
     decoder: Option<Box<dyn Decoder>>,
@@ -335,10 +337,11 @@ pub struct Tokenizer<M, N> {
     padding: Option<PaddingParams>,
 }
 
-impl<M, N> Tokenizer<M, N>
+impl<M, N, PT> Tokenizer<M, N, PT>
 where
     M: Model,
     N: Normalizer,
+    PT: PreTokenizer,
 {
     /// Instantiate a new Tokenizer, with the given Model
     pub fn new(model: M) -> Self {
@@ -368,14 +371,13 @@ where
     }
 
     /// Set the pre tokenizer
-    pub fn with_pre_tokenizer(&mut self, pre_tokenizer: Box<dyn PreTokenizer>) -> &Self {
+    pub fn with_pre_tokenizer(&mut self, pre_tokenizer: PT) -> &Self {
         self.pre_tokenizer = Some(pre_tokenizer);
         self
     }
 
     /// Get the pre tokenizer
-    #[allow(clippy::borrowed_box)]
-    pub fn get_pre_tokenizer(&self) -> Option<&Box<dyn PreTokenizer>> {
+    pub fn get_pre_tokenizer(&self) -> Option<&PT> {
         self.pre_tokenizer.as_ref()
     }
 
@@ -577,7 +579,8 @@ where
     /// # use tokenizers::Tokenizer;
     /// # use tokenizers::models::bpe::BPE;
     /// # use tokenizers::normalizers::NormalizerWrapper;
-    /// # let mut tokenizer = Tokenizer::<_, NormalizerWrapper>::new(BPE::default());
+    /// # use tokenizers::pre_tokenizers::PreTokenizerWrapper;
+    /// # let mut tokenizer = Tokenizer::<_, NormalizerWrapper, PreTokenizerWrapper>::new(BPE::default());
     /// #
     /// // Sequences:
     /// tokenizer.encode("Single sequence", false);
@@ -752,7 +755,7 @@ where
     }
 
     /// Train a model and replace our current Model, using the given Trainer
-    pub fn train<T, TM>(self, trainer: &T, files: Vec<String>) -> Result<Tokenizer<TM, N>>
+    pub fn train<T, TM>(self, trainer: &T, files: Vec<String>) -> Result<Tokenizer<TM, N, PT>>
     where
         T: Trainer<Model = TM>,
         TM: Model,
@@ -912,10 +915,11 @@ where
     }
 }
 
-impl<M, N> std::str::FromStr for Tokenizer<M, N>
+impl<M, N, PT> std::str::FromStr for Tokenizer<M, N, PT>
 where
     M: for<'de> Deserialize<'de> + Model,
     N: for<'de> Deserialize<'de> + Normalizer,
+    PT: for<'de> Deserialize<'de> + PreTokenizer,
 {
     type Err = Error;
 
@@ -924,10 +928,11 @@ where
     }
 }
 
-impl<M, N> Tokenizer<M, N>
+impl<M, N, PT> Tokenizer<M, N, PT>
 where
     M: DeserializeOwned + Model,
     N: DeserializeOwned + Normalizer,
+    PT: DeserializeOwned + PreTokenizer,
 {
     /// Instantiate a new Tokenizer from the given file
     pub fn from_file<P: AsRef<Path>>(file: P) -> Result<Self> {
@@ -937,10 +942,11 @@ where
     }
 }
 
-impl<M, N> Tokenizer<M, N>
+impl<M, N, PT> Tokenizer<M, N, PT>
 where
     M: Serialize,
     N: Serialize,
+    PT: Serialize,
 {
     /// Serialize the current tokenizer as a String
     pub fn to_string(&self, pretty: bool) -> Result<String> {
diff --git a/tokenizers/src/tokenizer/serialization.rs b/tokenizers/src/tokenizer/serialization.rs
index 07ec106a..473f32bf 100644
--- a/tokenizers/src/tokenizer/serialization.rs
+++ b/tokenizers/src/tokenizer/serialization.rs
@@ -8,14 +8,15 @@ use serde::{
 };
 
 use super::{added_vocabulary::AddedTokenWithId, Tokenizer};
-use crate::{Model, Normalizer, TokenizerBuilder};
+use crate::{Model, Normalizer, PreTokenizer, TokenizerBuilder};
 
 static SERIALIZATION_VERSION: &str = "1.0";
 
-impl<M, N> Serialize for Tokenizer<M, N>
+impl<M, N, PT> Serialize for Tokenizer<M, N, PT>
 where
     M: Serialize,
     N: Serialize,
+    PT: Serialize,
 {
     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
     where
@@ -44,10 +45,11 @@ where
     }
 }
 
-impl<'de, M, N> Deserialize<'de> for Tokenizer<M, N>
+impl<'de, M, N, PT> Deserialize<'de> for Tokenizer<M, N, PT>
 where
     M: Deserialize<'de> + Model,
     N: Deserialize<'de> + Normalizer,
+    PT: Deserialize<'de> + PreTokenizer,
 {
     fn deserialize<De>(deserializer: De) -> Result<Self, De::Error>
     where
@@ -66,19 +68,20 @@ where
                 "decoder",
                 "model",
             ],
-            TokenizerVisitor(PhantomData, PhantomData),
+            TokenizerVisitor(PhantomData, PhantomData, PhantomData),
         )
     }
 }
 
-struct TokenizerVisitor<M, N>(PhantomData<M>, PhantomData<N>);
+struct TokenizerVisitor<M, N, PT>(PhantomData<M>, PhantomData<N>, PhantomData<PT>);
 
-impl<'de, M, N> Visitor<'de> for TokenizerVisitor<M, N>
+impl<'de, M, N, PT> Visitor<'de> for TokenizerVisitor<M, N, PT>
 where
     M: Deserialize<'de> + Model,
     N: Deserialize<'de> + Normalizer,
+    PT: Deserialize<'de> + PreTokenizer,
 {
-    type Value = Tokenizer<M, N>;
+    type Value = Tokenizer<M, N, PT>;
 
     fn expecting(&self, fmt: &mut std::fmt::Formatter) -> std::fmt::Result {
         write!(fmt, "struct Tokenizer")
diff --git a/tokenizers/tests/common/mod.rs b/tokenizers/tests/common/mod.rs
index e78a1ead..1afd563e 100644
--- a/tokenizers/tests/common/mod.rs
+++ b/tokenizers/tests/common/mod.rs
@@ -5,11 +5,12 @@ use tokenizers::normalizers::bert::BertNormalizer;
 use tokenizers::normalizers::NormalizerWrapper;
 use tokenizers::pre_tokenizers::bert::BertPreTokenizer;
 use tokenizers::pre_tokenizers::byte_level::ByteLevel;
+use tokenizers::pre_tokenizers::PreTokenizerWrapper;
 use tokenizers::processors::bert::BertProcessing;
 use tokenizers::tokenizer::{Model, Tokenizer};
 
 #[allow(dead_code)]
-pub fn get_empty() -> Tokenizer<BPE, NormalizerWrapper> {
+pub fn get_empty() -> Tokenizer<BPE, NormalizerWrapper, PreTokenizerWrapper> {
     Tokenizer::new(BPE::default())
 }
 
@@ -24,11 +25,9 @@ pub fn get_byte_level_bpe() -> BPE {
 pub fn get_byte_level(
     add_prefix_space: bool,
     trim_offsets: bool,
-) -> Tokenizer<BPE, NormalizerWrapper> {
+) -> Tokenizer<BPE, NormalizerWrapper, ByteLevel> {
     let mut tokenizer = Tokenizer::new(get_byte_level_bpe());
-    tokenizer.with_pre_tokenizer(Box::new(
-        ByteLevel::default().add_prefix_space(add_prefix_space),
-    ));
+    tokenizer.with_pre_tokenizer(ByteLevel::default().add_prefix_space(add_prefix_space));
     tokenizer.with_decoder(Box::new(ByteLevel::default()));
     tokenizer.with_post_processor(Box::new(ByteLevel::default().trim_offsets(trim_offsets)));
 
@@ -43,10 +42,10 @@ pub fn get_bert_wordpiece() -> WordPiece {
 }
 
 #[allow(dead_code)]
-pub fn get_bert() -> Tokenizer<WordPiece, BertNormalizer> {
+pub fn get_bert() -> Tokenizer<WordPiece, BertNormalizer, BertPreTokenizer> {
     let mut tokenizer = Tokenizer::new(get_bert_wordpiece());
     tokenizer.with_normalizer(BertNormalizer::default());
-    tokenizer.with_pre_tokenizer(Box::new(BertPreTokenizer));
+    tokenizer.with_pre_tokenizer(BertPreTokenizer);
     tokenizer.with_decoder(Box::new(WordPieceDecoder::default()));
     tokenizer.with_post_processor(Box::new(BertProcessing::new(
         (