diff --git a/Cargo.toml b/Cargo.toml
index 8f91409b..854027e0 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -23,6 +23,7 @@ selectors = "0.23.0"
 smallvec = "1.9.0"
 tendril = "0.4.3"
 indexmap = { version = "1.9.1", optional = true }
+ahash = "0.8"
 
 [dependencies.getopts]
 version = "0.2.21"
diff --git a/src/main.rs b/src/main.rs
index 66fe2895..9d4684b3 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -129,5 +129,5 @@ fn main() {
             .any(|m| m)
     };
 
-    process::exit(if matched { 0 } else { 1 });
+    process::exit(i32::from(!matched));
 }
diff --git a/src/node.rs b/src/node.rs
index 78d5f940..c0eb9ec3 100644
--- a/src/node.rs
+++ b/src/node.rs
@@ -1,7 +1,7 @@
 //! HTML nodes.
 
+use ahash::{HashMap, HashSet};
 use std::collections::{hash_map, hash_set};
-use std::collections::{HashMap, HashSet};
 use std::fmt;
 use std::ops::Deref;
 
@@ -223,10 +223,10 @@ pub struct Element {
     pub name: QualName,
 
     /// The element ID.
-    pub id: Option<LocalName>,
+    pub id: Option<String>,
 
     /// The element classes.
-    pub classes: HashSet<LocalName>,
+    pub classes: HashSet<String>,
 
     /// The element attributes.
     pub attrs: Attributes,
@@ -238,16 +238,16 @@ impl Element {
         let id = attrs
             .iter()
             .find(|a| a.name.local.deref() == "id")
-            .map(|a| LocalName::from(a.value.deref()));
+            .map(|a| String::from(a.value.deref()));
 
-        let classes: HashSet<LocalName> = attrs
+        let classes: HashSet<String> = attrs
             .iter()
             .find(|a| a.name.local.deref() == "class")
-            .map_or(HashSet::new(), |a| {
+            .map_or(HashSet::default(), |a| {
                 a.value
                     .deref()
                     .split_whitespace()
-                    .map(LocalName::from)
+                    .map(String::from)
                     .collect()
             });
 
@@ -300,7 +300,7 @@ impl Element {
 #[allow(missing_debug_implementations)]
 #[derive(Clone)]
 pub struct Classes<'a> {
-    inner: hash_set::Iter<'a, LocalName>,
+    inner: hash_set::Iter<'a, String>,
 }
 
 impl<'a> Iterator for Classes<'a> {
diff --git a/src/selector.rs b/src/selector.rs
index a33c2a9c..dabc9fa7 100644
--- a/src/selector.rs
+++ b/src/selector.rs
@@ -67,6 +67,8 @@ impl<'i> parser::Parser<'i> for Parser {
 pub struct Simple;
 
 impl parser::SelectorImpl for Simple {
+    // see: https://github.com/servo/servo/pull/19747#issuecomment-357106065
+    type ExtraMatchingData = String;
     type AttrValue = CssString;
     type Identifier = CssLocalName;
     type LocalName = CssLocalName;
@@ -74,12 +76,9 @@ impl parser::SelectorImpl for Simple {
     type NamespaceUrl = Namespace;
     type BorrowedNamespaceUrl = Namespace;
     type BorrowedLocalName = CssLocalName;
-
     type NonTSPseudoClass = NonTSPseudoClass;
-    type PseudoElement = PseudoElement;
 
-    // see: https://github.com/servo/servo/pull/19747#issuecomment-357106065
-    type ExtraMatchingData = String;
+    type PseudoElement = PseudoElement;
 }
 
 /// Wraps [`String`] so that it can be used with [`selectors`]