diff --git a/Cargo.toml b/Cargo.toml
index 0be3f600e4..347ccd54e6 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -77,7 +77,7 @@ proptest = "1.0.0"
 criterion = "0.5"
 test-log = "0.2.10"
 env_logger = "0.10.0"
-pprof = { version = "0.11.0", features = ["flamegraph", "criterion"] }
+pprof = { git = "https://github.com/PSeitz/pprof-rs/", rev = "7a92207", features = ["flamegraph", "criterion"] } # temp fork that works with criterion 0.5
 futures = "0.3.21"
 paste = "1.0.11"
 more-asserts = "0.3.1"
diff --git a/src/tokenizer/alphanum_only.rs b/src/tokenizer/alphanum_only.rs
index abca2f671a..b40731fd34 100644
--- a/src/tokenizer/alphanum_only.rs
+++ b/src/tokenizer/alphanum_only.rs
@@ -50,9 +50,9 @@ impl TokenFilter for AlphaNumOnlyFilter {
 pub struct AlphaNumOnlyFilterWrapper<T>(T);
 
 impl<T: Tokenizer> Tokenizer for AlphaNumOnlyFilterWrapper<T> {
-    type TokenStream<'a, 'b> = AlphaNumOnlyFilterStream<T::TokenStream<'a, 'b>>;
+    type TokenStream<'a> = AlphaNumOnlyFilterStream<T::TokenStream<'a>>;
 
-    fn token_stream<'a, 'b>(&'b mut self, text: &'a str) -> Self::TokenStream<'a, 'b> {
+    fn token_stream<'a>(&'a mut self, text: &'a str) -> Self::TokenStream<'a> {
         AlphaNumOnlyFilterStream {
             tail: self.0.token_stream(text),
         }
diff --git a/src/tokenizer/ascii_folding_filter.rs b/src/tokenizer/ascii_folding_filter.rs
index 65fa51df1f..4b3655febf 100644
--- a/src/tokenizer/ascii_folding_filter.rs
+++ b/src/tokenizer/ascii_folding_filter.rs
@@ -20,9 +20,9 @@ impl TokenFilter for AsciiFoldingFilter {
 pub struct AsciiFoldingFilterWrapper<T>(T);
 
 impl<T: Tokenizer> Tokenizer for AsciiFoldingFilterWrapper<T> {
-    type TokenStream<'a, 'b> = AsciiFoldingFilterTokenStream<T::TokenStream<'a, 'b>>;
+    type TokenStream<'a> = AsciiFoldingFilterTokenStream<T::TokenStream<'a>>;
 
-    fn token_stream<'a, 'b>(&'b mut self, text: &'a str) -> Self::TokenStream<'a, 'b> {
+    fn token_stream<'a>(&'a mut self, text: &'a str) -> Self::TokenStream<'a> {
         AsciiFoldingFilterTokenStream {
             buffer: String::with_capacity(100),
             tail: self.0.token_stream(text),
diff --git a/src/tokenizer/empty_tokenizer.rs b/src/tokenizer/empty_tokenizer.rs
index deee002070..46cb78c10d 100644
--- a/src/tokenizer/empty_tokenizer.rs
+++ b/src/tokenizer/empty_tokenizer.rs
@@ -4,7 +4,7 @@ use crate::tokenizer::{Token, TokenStream, Tokenizer};
 pub(crate) struct EmptyTokenizer;
 
 impl Tokenizer for EmptyTokenizer {
-    type TokenStream<'a, 'b> = EmptyTokenStream;
+    type TokenStream<'a> = EmptyTokenStream;
     fn token_stream(&mut self, _text: &str) -> EmptyTokenStream {
         EmptyTokenStream::default()
     }
diff --git a/src/tokenizer/facet_tokenizer.rs b/src/tokenizer/facet_tokenizer.rs
index 01bd659eea..568d60ae31 100644
--- a/src/tokenizer/facet_tokenizer.rs
+++ b/src/tokenizer/facet_tokenizer.rs
@@ -21,15 +21,15 @@ enum State {
     Terminated,
 }
 
-pub struct FacetTokenStream<'a, 'b> {
+pub struct FacetTokenStream<'a> {
     text: &'a str,
     state: State,
-    token: &'b mut Token,
+    token: &'a mut Token,
 }
 
 impl Tokenizer for FacetTokenizer {
-    type TokenStream<'a, 'b> = FacetTokenStream<'a, 'b>;
-    fn token_stream<'a, 'b>(&'b mut self, text: &'a str) -> FacetTokenStream<'a, 'b> {
+    type TokenStream<'a> = FacetTokenStream<'a>;
+    fn token_stream<'a>(&'a mut self, text: &'a str) -> FacetTokenStream<'a> {
         self.token.reset();
         self.token.position = 0;
         FacetTokenStream {
@@ -40,7 +40,7 @@ impl Tokenizer for FacetTokenizer {
     }
 }
 
-impl<'a, 'b> TokenStream for FacetTokenStream<'a, 'b> {
+impl<'a> TokenStream for FacetTokenStream<'a> {
     fn advance(&mut self) -> bool {
         match self.state {
             State::RootFacetNotEmitted => {
diff --git a/src/tokenizer/lower_caser.rs b/src/tokenizer/lower_caser.rs
index a0efe68b4b..18696b6b75 100644
--- a/src/tokenizer/lower_caser.rs
+++ b/src/tokenizer/lower_caser.rs
@@ -18,9 +18,9 @@ impl TokenFilter for LowerCaser {
 pub struct LowerCaserFilter<T>(T);
 
 impl<T: Tokenizer> Tokenizer for LowerCaserFilter<T> {
-    type TokenStream<'a, 'b> = LowerCaserTokenStream<T::TokenStream<'a, 'b>>;
+    type TokenStream<'a> = LowerCaserTokenStream<T::TokenStream<'a>>;
 
-    fn token_stream<'a, 'b>(&'b mut self, text: &'a str) -> Self::TokenStream<'a, 'b> {
+    fn token_stream<'a>(&'a mut self, text: &'a str) -> Self::TokenStream<'a> {
         LowerCaserTokenStream {
             tail: self.0.token_stream(text),
             buffer: String::new(), // TODO move to global buffer
diff --git a/src/tokenizer/ngram_tokenizer.rs b/src/tokenizer/ngram_tokenizer.rs
index e3e4cd59a7..ae54cacf4f 100644
--- a/src/tokenizer/ngram_tokenizer.rs
+++ b/src/tokenizer/ngram_tokenizer.rs
@@ -121,7 +121,7 @@ impl NgramTokenizer {
 }
 
 /// TokenStream associate to the `NgramTokenizer`
-pub struct NgramTokenStream<'a, 'b> {
+pub struct NgramTokenStream<'a> {
     /// parameters
     ngram_charidx_iterator: StutteringIterator<CodepointFrontiers<'a>>,
     /// true if the NgramTokenStream is in prefix mode.
@@ -129,12 +129,12 @@ pub struct NgramTokenStream<'a, 'b> {
     /// input
     text: &'a str,
     /// output
-    token: &'b mut Token,
+    token: &'a mut Token,
 }
 
 impl Tokenizer for NgramTokenizer {
-    type TokenStream<'a, 'b> = NgramTokenStream<'a, 'b>;
-    fn token_stream<'a, 'b>(&'b mut self, text: &'a str) -> NgramTokenStream<'a, 'b> {
+    type TokenStream<'a> = NgramTokenStream<'a>;
+    fn token_stream<'a>(&'a mut self, text: &'a str) -> NgramTokenStream<'a> {
         self.token.reset();
         NgramTokenStream {
             ngram_charidx_iterator: StutteringIterator::new(
@@ -149,7 +149,7 @@ impl Tokenizer for NgramTokenizer {
     }
 }
 
-impl<'a, 'b> TokenStream for NgramTokenStream<'a, 'b> {
+impl<'a> TokenStream for NgramTokenStream<'a> {
     fn advance(&mut self) -> bool {
         if let Some((offset_from, offset_to)) = self.ngram_charidx_iterator.next() {
             if self.prefix_only && offset_from > 0 {
diff --git a/src/tokenizer/raw_tokenizer.rs b/src/tokenizer/raw_tokenizer.rs
index 07079abf20..9bf7ee22a9 100644
--- a/src/tokenizer/raw_tokenizer.rs
+++ b/src/tokenizer/raw_tokenizer.rs
@@ -12,7 +12,7 @@ pub struct RawTokenStream<'a> {
 }
 
 impl Tokenizer for RawTokenizer {
-    type TokenStream<'b, 'a> = RawTokenStream<'a>;
+    type TokenStream<'a> = RawTokenStream<'a>;
     fn token_stream<'a>(&'a mut self, text: &str) -> RawTokenStream<'a> {
         self.token.reset();
         self.token.position = 0;
diff --git a/src/tokenizer/regex_tokenizer.rs b/src/tokenizer/regex_tokenizer.rs
index cd502a55d3..f9a10ad201 100644
--- a/src/tokenizer/regex_tokenizer.rs
+++ b/src/tokenizer/regex_tokenizer.rs
@@ -64,8 +64,8 @@ impl RegexTokenizer {
 }
 
 impl Tokenizer for RegexTokenizer {
-    type TokenStream<'a, 'b> = RegexTokenStream<'a, 'b>;
-    fn token_stream<'a, 'b>(&'b mut self, text: &'a str) -> RegexTokenStream<'a, 'b> {
+    type TokenStream<'a> = RegexTokenStream<'a>;
+    fn token_stream<'a>(&'a mut self, text: &'a str) -> RegexTokenStream<'a> {
         self.token.reset();
         RegexTokenStream {
             regex: self.regex.clone(),
@@ -76,14 +76,14 @@ impl Tokenizer for RegexTokenizer {
     }
 }
 
-pub struct RegexTokenStream<'a, 'b> {
+pub struct RegexTokenStream<'a> {
     regex: Regex,
     text: &'a str,
-    token: &'b mut Token,
+    token: &'a mut Token,
     cursor: usize,
 }
 
-impl<'a, 'b> TokenStream for RegexTokenStream<'a, 'b> {
+impl<'a> TokenStream for RegexTokenStream<'a> {
     fn advance(&mut self) -> bool {
         let Some(regex_match) = self.regex.find(self.text) else {
             return false;
@@ -105,11 +105,11 @@ impl<'a, 'b> TokenStream for RegexTokenStream<'a, 'b> {
     }
 
     fn token(&self) -> &Token {
-        &self.token
+        self.token
     }
 
     fn token_mut(&mut self) -> &mut Token {
-        &mut self.token
+        self.token
     }
 }
 
diff --git a/src/tokenizer/remove_long.rs b/src/tokenizer/remove_long.rs
index d18f57450b..78f3e731ac 100644
--- a/src/tokenizer/remove_long.rs
+++ b/src/tokenizer/remove_long.rs
@@ -55,9 +55,9 @@ pub struct RemoveLongFilterWrapper<T: Tokenizer> {
 }
 
 impl<T: Tokenizer> Tokenizer for RemoveLongFilterWrapper<T> {
-    type TokenStream<'a, 'b> = RemoveLongFilterStream<T::TokenStream<'a, 'b>>;
+    type TokenStream<'a> = RemoveLongFilterStream<T::TokenStream<'a>>;
 
-    fn token_stream<'a, 'b>(&'b mut self, text: &'a str) -> Self::TokenStream<'a, 'b> {
+    fn token_stream<'a>(&'a mut self, text: &'a str) -> Self::TokenStream<'a> {
         RemoveLongFilterStream {
             token_length_limit: self.length_limit,
             tail: self.inner.token_stream(text),
diff --git a/src/tokenizer/simple_tokenizer.rs b/src/tokenizer/simple_tokenizer.rs
index ff49efa38e..540dfac477 100644
--- a/src/tokenizer/simple_tokenizer.rs
+++ b/src/tokenizer/simple_tokenizer.rs
@@ -9,15 +9,15 @@ pub struct SimpleTokenizer {
 }
 
 /// TokenStream produced by the `SimpleTokenizer`.
-pub struct SimpleTokenStream<'a, 'b> {
+pub struct SimpleTokenStream<'a> {
     text: &'a str,
     chars: CharIndices<'a>,
-    token: &'b mut Token,
+    token: &'a mut Token,
 }
 
 impl Tokenizer for SimpleTokenizer {
-    type TokenStream<'a, 'b> = SimpleTokenStream<'a, 'b>;
-    fn token_stream<'a, 'b>(&'b mut self, text: &'a str) -> SimpleTokenStream<'a, 'b> {
+    type TokenStream<'a> = SimpleTokenStream<'a>;
+    fn token_stream<'a>(&'a mut self, text: &'a str) -> SimpleTokenStream<'a> {
         self.token.reset();
         SimpleTokenStream {
             text,
@@ -27,7 +27,7 @@ impl Tokenizer for SimpleTokenizer {
     }
 }
 
-impl<'a, 'b> SimpleTokenStream<'a, 'b> {
+impl<'a> SimpleTokenStream<'a> {
     // search for the end of the current token.
     fn search_token_end(&mut self) -> usize {
         (&mut self.chars)
@@ -38,7 +38,7 @@ impl<'a, 'b> SimpleTokenStream<'a, 'b> {
     }
 }
 
-impl<'a, 'b> TokenStream for SimpleTokenStream<'a, 'b> {
+impl<'a> TokenStream for SimpleTokenStream<'a> {
     fn advance(&mut self) -> bool {
         self.token.text.clear();
         self.token.position = self.token.position.wrapping_add(1);
diff --git a/src/tokenizer/split_compound_words.rs b/src/tokenizer/split_compound_words.rs
index b2366b10b7..bcde161cc8 100644
--- a/src/tokenizer/split_compound_words.rs
+++ b/src/tokenizer/split_compound_words.rs
@@ -97,9 +97,9 @@ pub struct SplitCompoundWordsFilter<T> {
 }
 
 impl<T: Tokenizer> Tokenizer for SplitCompoundWordsFilter<T> {
-    type TokenStream<'a, 'b> = SplitCompoundWordsTokenStream<T::TokenStream<'a, 'b>>;
+    type TokenStream<'a> = SplitCompoundWordsTokenStream<T::TokenStream<'a>>;
 
-    fn token_stream<'a, 'b>(&'b mut self, text: &'a str) -> Self::TokenStream<'a, 'b> {
+    fn token_stream<'a>(&'a mut self, text: &'a str) -> Self::TokenStream<'a> {
         SplitCompoundWordsTokenStream {
             dict: self.dict.clone(),
             tail: self.inner.token_stream(text),
diff --git a/src/tokenizer/stemmer.rs b/src/tokenizer/stemmer.rs
index 081fd6be4e..4c43b609ab 100644
--- a/src/tokenizer/stemmer.rs
+++ b/src/tokenizer/stemmer.rs
@@ -98,9 +98,9 @@ pub struct StemmerFilter<T> {
 }
 
 impl<T: Tokenizer> Tokenizer for StemmerFilter<T> {
-    type TokenStream<'a, 'b> = StemmerTokenStream<T::TokenStream<'a, 'b>>;
+    type TokenStream<'a> = StemmerTokenStream<T::TokenStream<'a>>;
 
-    fn token_stream<'a, 'b>(&'b mut self, text: &'a str) -> Self::TokenStream<'a, 'b> {
+    fn token_stream<'a>(&'a mut self, text: &'a str) -> Self::TokenStream<'a> {
         let stemmer = rust_stemmers::Stemmer::create(self.stemmer_algorithm);
         StemmerTokenStream {
             tail: self.inner.token_stream(text),
diff --git a/src/tokenizer/stop_word_filter/mod.rs b/src/tokenizer/stop_word_filter/mod.rs
index a1b894130c..80f1fe4938 100644
--- a/src/tokenizer/stop_word_filter/mod.rs
+++ b/src/tokenizer/stop_word_filter/mod.rs
@@ -88,9 +88,9 @@ pub struct StopWordFilterWrapper<T> {
 }
 
 impl<T: Tokenizer> Tokenizer for StopWordFilterWrapper<T> {
-    type TokenStream<'a, 'b> = StopWordFilterStream<T::TokenStream<'a, 'b>>;
+    type TokenStream<'a> = StopWordFilterStream<T::TokenStream<'a>>;
 
-    fn token_stream<'a, 'b>(&'b mut self, text: &'a str) -> Self::TokenStream<'a, 'b> {
+    fn token_stream<'a>(&'a mut self, text: &'a str) -> Self::TokenStream<'a> {
         StopWordFilterStream {
             words: self.words.clone(),
             tail: self.inner.token_stream(text),
diff --git a/src/tokenizer/tokenizer.rs b/src/tokenizer/tokenizer.rs
index 2c70969899..ccab6cda73 100644
--- a/src/tokenizer/tokenizer.rs
+++ b/src/tokenizer/tokenizer.rs
@@ -12,13 +12,13 @@ pub struct TextAnalyzer {
 /// A boxable `Tokenizer`, with its `TokenStream` type erased.
 trait BoxableTokenizer: 'static + Send + Sync {
     /// Creates a boxed token stream for a given `str`.
-    fn box_token_stream<'a, 'b: 'a>(&'b mut self, text: &'a str) -> BoxTokenStream<'a>;
+    fn box_token_stream<'a>(&'a mut self, text: &'a str) -> BoxTokenStream<'a>;
     /// Clone this tokenizer.
     fn box_clone(&self) -> Box<dyn BoxableTokenizer>;
 }
 
 impl<T: Tokenizer> BoxableTokenizer for T {
-    fn box_token_stream<'a, 'b: 'a>(&'b mut self, text: &'a str) -> BoxTokenStream<'a> {
+    fn box_token_stream<'a>(&'a mut self, text: &'a str) -> BoxTokenStream<'a> {
         self.token_stream(text).into()
     }
     fn box_clone(&self) -> Box<dyn BoxableTokenizer> {
@@ -53,7 +53,7 @@ impl TextAnalyzer {
     }
 
     /// Creates a token stream for a given `str`.
-    pub fn token_stream<'a, 'b: 'a>(&'b mut self, text: &'a str) -> BoxTokenStream<'a> {
+    pub fn token_stream<'a>(&'a mut self, text: &'a str) -> BoxTokenStream<'a> {
         self.tokenizer.box_token_stream(text)
     }
 }
diff --git a/src/tokenizer/whitespace_tokenizer.rs b/src/tokenizer/whitespace_tokenizer.rs
index 8b411ad054..69a3b05509 100644
--- a/src/tokenizer/whitespace_tokenizer.rs
+++ b/src/tokenizer/whitespace_tokenizer.rs
@@ -8,15 +8,15 @@ pub struct WhitespaceTokenizer {
     token: Token,
 }
 
-pub struct WhitespaceTokenStream<'a, 'b> {
+pub struct WhitespaceTokenStream<'a> {
     text: &'a str,
     chars: CharIndices<'a>,
-    token: &'b mut Token,
+    token: &'a mut Token,
 }
 
 impl Tokenizer for WhitespaceTokenizer {
-    type TokenStream<'a, 'b> = WhitespaceTokenStream<'a, 'b>;
-    fn token_stream<'a, 'b>(&'b mut self, text: &'a str) -> WhitespaceTokenStream<'a, 'b> {
+    type TokenStream<'a> = WhitespaceTokenStream<'a>;
+    fn token_stream<'a>(&'a mut self, text: &'a str) -> WhitespaceTokenStream<'a> {
         self.token.reset();
         WhitespaceTokenStream {
             text,
@@ -26,7 +26,7 @@ impl Tokenizer for WhitespaceTokenizer {
     }
 }
 
-impl<'a, 'b> WhitespaceTokenStream<'a, 'b> {
+impl<'a> WhitespaceTokenStream<'a> {
     // search for the end of the current token.
     fn search_token_end(&mut self) -> usize {
         (&mut self.chars)
@@ -37,7 +37,7 @@ impl<'a, 'b> WhitespaceTokenStream<'a, 'b> {
     }
 }
 
-impl<'a, 'b> TokenStream for WhitespaceTokenStream<'a, 'b> {
+impl<'a> TokenStream for WhitespaceTokenStream<'a> {
     fn advance(&mut self) -> bool {
         self.token.text.clear();
         self.token.position = self.token.position.wrapping_add(1);
diff --git a/tokenizer-api/src/lib.rs b/tokenizer-api/src/lib.rs
index ab0fa8c955..e563443715 100644
--- a/tokenizer-api/src/lib.rs
+++ b/tokenizer-api/src/lib.rs
@@ -55,9 +55,9 @@ impl Token {
 /// before indexing.
 pub trait Tokenizer: 'static + Clone + Send + Sync {
     /// The token stream returned by this Tokenizer.
-    type TokenStream<'a, 'b>: TokenStream;
+    type TokenStream<'a>: TokenStream;
     /// Creates a token stream for a given `str`.
-    fn token_stream<'a, 'b>(&'b mut self, text: &'a str) -> Self::TokenStream<'a, 'b>;
+    fn token_stream<'a>(&'a mut self, text: &'a str) -> Self::TokenStream<'a>;
 }
 
 /// Simple wrapper of `Box<dyn TokenStream + 'a>`.