diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index b08ddef7..a7be6aec 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -22,6 +22,7 @@ jobs:
         features:
           -
           - --features dummy_match_byte
+          - --features malloc_size_of
         include:
           - toolchain: nightly
             features: --features bench
diff --git a/Cargo.toml b/Cargo.toml
index f783f19f..6604f20e 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "cssparser"
-version = "0.34.0"
+version = "0.35.0"
 authors = ["Simon Sapin <simon.sapin@exyr.org>"]
 
 description = "Rust implementation of CSS Syntax Level 3"
@@ -25,6 +25,7 @@ dtoa-short = "0.3"
 itoa = "1.0"
 phf = { version = "0.11.2", features = ["macros"] }
 serde = { version = "1.0", features = ["derive"], optional = true }
+malloc_size_of = { version = "0.1", default-features = false, optional = true }
 smallvec = "1.0"
 
 [profile.profiling]
diff --git a/color/Cargo.toml b/color/Cargo.toml
index d5cde913..5dd6aac7 100644
--- a/color/Cargo.toml
+++ b/color/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "cssparser-color"
-version = "0.2.0"
+version = "0.3.0"
 authors = ["Emilio Cobos Álvarez <emilio@crisal.io>"]
 description = "Color implementation based on cssparser"
 documentation = "https://docs.rs/cssparser-color/"
@@ -12,7 +12,7 @@ edition = "2021"
 path = "lib.rs"
 
 [dependencies]
-cssparser = { path = "..", version = "0.34" }
+cssparser = { path = "..", version = "0.35" }
 serde = { version = "1.0", features = ["derive"], optional = true }
 
 [features]
diff --git a/src/from_bytes.rs b/src/from_bytes.rs
index 78a56d3e..7d9d2c76 100644
--- a/src/from_bytes.rs
+++ b/src/from_bytes.rs
@@ -24,9 +24,9 @@ pub trait EncodingSupport {
 ///
 /// * `css_bytes`: A byte string.
 /// * `protocol_encoding`: The encoding label, if any, defined by HTTP or equivalent protocol.
-///     (e.g. via the `charset` parameter of the `Content-Type` header.)
+///   (e.g. via the `charset` parameter of the `Content-Type` header.)
 /// * `environment_encoding`: An optional `Encoding` object for the [environment encoding]
-///     (https://drafts.csswg.org/css-syntax/#environment-encoding), if any.
+///   (https://drafts.csswg.org/css-syntax/#environment-encoding), if any.
 ///
 /// Returns the encoding to use.
 pub fn stylesheet_encoding<E>(
diff --git a/src/rules_and_declarations.rs b/src/rules_and_declarations.rs
index 188e354e..bdaef077 100644
--- a/src/rules_and_declarations.rs
+++ b/src/rules_and_declarations.rs
@@ -49,6 +49,7 @@ pub trait DeclarationParser<'i> {
         &mut self,
         name: CowRcStr<'i>,
         input: &mut Parser<'i, 't>,
+        _declaration_start: &ParserState,
     ) -> Result<Self::Declaration, ParseError<'i, Self::Error>> {
         Err(input.new_error(BasicParseErrorKind::UnexpectedToken(Token::Ident(name))))
     }
@@ -279,7 +280,7 @@ where
                             error_behavior,
                             |input| {
                                 input.expect_colon()?;
-                                parser.parse_value(name, input)
+                                parser.parse_value(name, input, &start)
                             },
                         )
                     };
@@ -408,12 +409,13 @@ pub fn parse_one_declaration<'i, 't, P, E>(
 where
     P: DeclarationParser<'i, Error = E>,
 {
+    let start = input.state();
     let start_position = input.position();
     input
         .parse_entirely(|input| {
             let name = input.expect_ident()?.clone();
             input.expect_colon()?;
-            parser.parse_value(name, input)
+            parser.parse_value(name, input, &start)
         })
         .map_err(|e| (e, input.slice_from(start_position)))
 }
diff --git a/src/serializer.rs b/src/serializer.rs
index 5df73954..6696a622 100644
--- a/src/serializer.rs
+++ b/src/serializer.rs
@@ -466,6 +466,9 @@ pub enum TokenSerializationType {
     Other,
 }
 
+#[cfg(feature = "malloc_size_of")]
+malloc_size_of::malloc_size_of_is_0!(TokenSerializationType);
+
 impl TokenSerializationType {
     /// Return a value that represents the absence of a token, e.g. before the start of the input.
     #[deprecated(
diff --git a/src/tests.rs b/src/tests.rs
index ec0fc517..3c122f0d 100644
--- a/src/tests.rs
+++ b/src/tests.rs
@@ -849,6 +849,7 @@ impl<'i> DeclarationParser<'i> for JsonParser {
         &mut self,
         name: CowRcStr<'i>,
         input: &mut Parser<'i, 't>,
+        _declaration_start: &ParserState,
     ) -> Result<Value, ParseError<'i, ()>> {
         let mut value = vec![];
         let mut important = false;
diff --git a/src/tokenizer.rs b/src/tokenizer.rs
index 2e86c66a..1c85e10a 100644
--- a/src/tokenizer.rs
+++ b/src/tokenizer.rs
@@ -533,6 +533,9 @@ impl<'a> Tokenizer<'a> {
 #[derive(PartialEq, Eq, PartialOrd, Ord, Debug, Clone, Copy)]
 pub struct SourcePosition(pub(crate) usize);
 
+#[cfg(feature = "malloc_size_of")]
+malloc_size_of::malloc_size_of_is_0!(SourcePosition);
+
 impl SourcePosition {
     /// Returns the current byte index in the original input.
     #[inline]
@@ -542,7 +545,7 @@ impl SourcePosition {
 }
 
 /// The line and column number for a given position within the input.
-#[derive(PartialEq, Eq, Debug, Clone, Copy)]
+#[derive(PartialEq, Eq, Debug, Clone, Copy, Default)]
 pub struct SourceLocation {
     /// The line number, starting at 0 for the first line.
     pub line: u32,
@@ -552,6 +555,9 @@ pub struct SourceLocation {
     pub column: u32,
 }
 
+#[cfg(feature = "malloc_size_of")]
+malloc_size_of::malloc_size_of_is_0!(SourceLocation);
+
 fn next_token<'a>(tokenizer: &mut Tokenizer<'a>) -> Result<Token<'a>, ()> {
     if tokenizer.is_eof() {
         return Err(());