diff --git a/ports/jniapi/build.rs b/ports/jniapi/build.rs
index 759c2376f20..896487d80d5 100644
--- a/ports/jniapi/build.rs
+++ b/ports/jniapi/build.rs
@@ -28,7 +28,7 @@ fn main() {
 
     // Generate GL bindings. For now, we only support EGL.
     if target.contains("android") {
-        let mut file = File::create(&dest.join("egl_bindings.rs")).unwrap();
+        let mut file = File::create(dest.join("egl_bindings.rs")).unwrap();
         Registry::new(Api::Egl, (1, 5), Profile::Core, Fallbacks::All, [])
             .write_bindings(gl_generator::StaticStructGenerator, &mut file)
             .unwrap();
@@ -38,6 +38,6 @@ fn main() {
     let mut default_prefs = PathBuf::from(env!("CARGO_MANIFEST_DIR"));
     default_prefs.push("../../resources/prefs.json");
     let prefs: Value = serde_json::from_reader(File::open(&default_prefs).unwrap()).unwrap();
-    let file = File::create(&dest.join("prefs.json")).unwrap();
+    let file = File::create(dest.join("prefs.json")).unwrap();
     serde_json::to_writer(file, &prefs).unwrap();
 }
diff --git a/ports/servoshell/app.rs b/ports/servoshell/app.rs
index 099b613ea62..1a7c1587657 100644
--- a/ports/servoshell/app.rs
+++ b/ports/servoshell/app.rs
@@ -84,11 +84,9 @@ impl App {
 
         // Handle browser state.
         let webviews = WebViewManager::new(window.clone());
-        let initial_url = get_default_url(
-            url.as_ref().map(String::as_str),
-            env::current_dir().unwrap(),
-            |path| fs::metadata(path).is_ok(),
-        );
+        let initial_url = get_default_url(url.as_deref(), env::current_dir().unwrap(), |path| {
+            fs::metadata(path).is_ok()
+        });
 
         let mut app = App {
             event_queue: RefCell::new(vec![]),
@@ -270,7 +268,7 @@ impl App {
                         window.winit_window().unwrap().request_redraw();
                     },
                     winit::event::Event::WindowEvent { ref event, .. } => {
-                        let response = minibrowser.on_event(&event);
+                        let response = minibrowser.on_event(event);
                         if response.repaint {
                             // Request a winit redraw event, so we can recomposite, update and paint
                             // the minibrowser, and present the new frame.
diff --git a/ports/servoshell/parser.rs b/ports/servoshell/parser.rs
index 860fe5a9484..e1a6334a5b9 100644
--- a/ports/servoshell/parser.rs
+++ b/ports/servoshell/parser.rs
@@ -28,17 +28,14 @@ pub fn get_default_url(
     // If the url is not provided, we fallback to the homepage in prefs,
     // or a blank page in case the homepage is not set either.
     let mut new_url = None;
-    let cmdline_url = url_opt
-        .clone()
-        .map(|s| s.to_string())
-        .and_then(|url_string| {
-            parse_url_or_filename(cwd.as_ref(), &url_string)
-                .map_err(|error| {
-                    warn!("URL parsing failed ({:?}).", error);
-                    error
-                })
-                .ok()
-        });
+    let cmdline_url = url_opt.map(|s| s.to_string()).and_then(|url_string| {
+        parse_url_or_filename(cwd.as_ref(), &url_string)
+            .map_err(|error| {
+                warn!("URL parsing failed ({:?}).", error);
+                error
+            })
+            .ok()
+    });
 
     if let Some(url) = cmdline_url.clone() {
         // Check if the URL path corresponds to a file
@@ -50,7 +47,7 @@ pub fn get_default_url(
         }
     }
 
-    if new_url.is_none() && !url_opt.is_none() {
+    if new_url.is_none() && url_opt.is_some() {
         new_url = location_bar_input_to_url(url_opt.unwrap());
     }
 
diff --git a/ports/servoshell/test.rs b/ports/servoshell/test.rs
index c715350c7b6..0ee94d44829 100644
--- a/ports/servoshell/test.rs
+++ b/ports/servoshell/test.rs
@@ -7,7 +7,7 @@ use std::path::Path;
 use crate::parser::{get_default_url, location_bar_input_to_url, parse_url_or_filename};
 
 #[cfg(not(target_os = "windows"))]
-const FAKE_CWD: &'static str = "/fake/cwd";
+const FAKE_CWD: &str = "/fake/cwd";
 
 #[cfg(target_os = "windows")]
 const FAKE_CWD: &'static str = "C:/fake/cwd";
diff --git a/support/crown/src/trace_in_no_trace.rs b/support/crown/src/trace_in_no_trace.rs
index 917a2c7459b..a0936e31278 100644
--- a/support/crown/src/trace_in_no_trace.rs
+++ b/support/crown/src/trace_in_no_trace.rs
@@ -127,7 +127,7 @@ fn incorrect_no_trace<'tcx, I: Into<MultiSpan> + Copy>(
         let recur_into_subtree = match t.kind() {
             ty::Adt(did, substs) => {
                 if let Some(pos) =
-                    get_must_not_have_traceable(sym, &cx.tcx.get_attrs_unchecked(did.did()))
+                    get_must_not_have_traceable(sym, cx.tcx.get_attrs_unchecked(did.did()))
                 {
                     let inner = substs.type_at(pos);
                     if inner.is_primitive_ty() {
@@ -169,7 +169,7 @@ impl<'tcx> LateLintPass<'tcx> for NotracePass {
             return;
         }*/
         if let hir::ItemKind::Struct(def, ..) = &item.kind {
-            for ref field in def.fields() {
+            for field in def.fields() {
                 let field_type = cx.tcx.type_of(field.def_id);
                 incorrect_no_trace(&self.symbols, cx, field_type.skip_binder(), field.span);
             }
diff --git a/support/crown/src/unrooted_must_root.rs b/support/crown/src/unrooted_must_root.rs
index d01ede4c0bb..5cef81f59a1 100644
--- a/support/crown/src/unrooted_must_root.rs
+++ b/support/crown/src/unrooted_must_root.rs
@@ -86,7 +86,7 @@ fn is_unrooted_ty<'tcx>(
         let recur_into_subtree = match t.kind() {
             ty::Adt(did, substs) => {
                 let has_attr =
-                    |did, name| has_lint_attr(sym, &cx.tcx.get_attrs_unchecked(did), name);
+                    |did, name| has_lint_attr(sym, cx.tcx.get_attrs_unchecked(did), name);
                 if has_attr(did.did(), sym.must_root) {
                     ret = true;
                     false
@@ -96,11 +96,7 @@ fn is_unrooted_ty<'tcx>(
                     // Rc<Promise> is okay
                     let inner = substs.type_at(0);
                     if let ty::Adt(did, _) = inner.kind() {
-                        if has_attr(did.did(), sym.allow_unrooted_in_rc) {
-                            false
-                        } else {
-                            true
-                        }
+                        !has_attr(did.did(), sym.allow_unrooted_in_rc)
                     } else {
                         true
                     }
@@ -185,11 +181,11 @@ impl<'tcx> LateLintPass<'tcx> for UnrootedPass {
     /// must be #[crown::unrooted_must_root_lint::must_root] themselves
     fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx hir::Item) {
         let attrs = cx.tcx.hir().attrs(item.hir_id());
-        if has_lint_attr(&self.symbols, &attrs, self.symbols.must_root) {
+        if has_lint_attr(&self.symbols, attrs, self.symbols.must_root) {
             return;
         }
         if let hir::ItemKind::Struct(def, ..) = &item.kind {
-            for ref field in def.fields() {
+            for field in def.fields() {
                 let field_type = cx.tcx.type_of(field.def_id);
                 if is_unrooted_ty(&self.symbols, cx, field_type.skip_binder(), false) {
                     cx.lint(
@@ -206,10 +202,10 @@ impl<'tcx> LateLintPass<'tcx> for UnrootedPass {
     /// All enums containing #[crown::unrooted_must_root_lint::must_root] types
     /// must be #[crown::unrooted_must_root_lint::must_root] themselves
     fn check_variant(&mut self, cx: &LateContext, var: &hir::Variant) {
-        let ref map = cx.tcx.hir();
+        let map = &cx.tcx.hir();
         let parent_item = map.expect_item(map.get_parent_item(var.hir_id).def_id);
         let attrs = cx.tcx.hir().attrs(parent_item.hir_id());
-        if !has_lint_attr(&self.symbols, &attrs, self.symbols.must_root) {
+        if !has_lint_attr(&self.symbols, attrs, self.symbols.must_root) {
             match var.data {
                 hir::VariantData::Tuple(fields, ..) => {
                     for field in fields {
@@ -241,7 +237,7 @@ impl<'tcx> LateLintPass<'tcx> for UnrootedPass {
     ) {
         let in_new_function = match kind {
             visit::FnKind::ItemFn(n, _, _) | visit::FnKind::Method(n, _) => {
-                &*n.as_str() == "new" || n.as_str().starts_with("new_")
+                n.as_str() == "new" || n.as_str().starts_with("new_")
             },
             visit::FnKind::Closure => return,
         };
@@ -271,7 +267,7 @@ impl<'tcx> LateLintPass<'tcx> for UnrootedPass {
             cx,
             in_new_function,
         };
-        visit::walk_expr(&mut visitor, &body.value);
+        visit::walk_expr(&mut visitor, body.value);
     }
 }
 
@@ -288,8 +284,8 @@ impl<'a, 'tcx> visit::Visitor<'tcx> for FnDefVisitor<'a, 'tcx> {
         let cx = self.cx;
 
         let require_rooted = |cx: &LateContext, in_new_function: bool, subexpr: &hir::Expr| {
-            let ty = cx.typeck_results().expr_ty(&subexpr);
-            if is_unrooted_ty(&self.symbols, cx, ty, in_new_function) {
+            let ty = cx.typeck_results().expr_ty(subexpr);
+            if is_unrooted_ty(self.symbols, cx, ty, in_new_function) {
                 cx.lint(
                     UNROOTED_MUST_ROOT,
                     format!("Expression of type {:?} must be rooted", ty),
@@ -300,7 +296,7 @@ impl<'a, 'tcx> visit::Visitor<'tcx> for FnDefVisitor<'a, 'tcx> {
 
         match expr.kind {
             // Trait casts from #[crown::unrooted_must_root_lint::must_root] types are not allowed
-            ExprKind::Cast(subexpr, _) => require_rooted(cx, self.in_new_function, &subexpr),
+            ExprKind::Cast(subexpr, _) => require_rooted(cx, self.in_new_function, subexpr),
             // This catches assignments... the main point of this would be to catch mutable
             // references to `JS<T>`.
             // FIXME: Enable this? Triggers on certain kinds of uses of DomRefCell.
diff --git a/tests/unit/style/parsing/selectors.rs b/tests/unit/style/parsing/selectors.rs
index 5e65bd504e6..edab3243b0a 100644
--- a/tests/unit/style/parsing/selectors.rs
+++ b/tests/unit/style/parsing/selectors.rs
@@ -9,8 +9,8 @@ use style::stylesheets::{Namespaces, Origin};
 use style_traits::ParseError;
 use url::Url;
 
-fn parse_selector<'i, 't>(
-    input: &mut Parser<'i, 't>,
+fn parse_selector<'i>(
+    input: &mut Parser<'i, '_>,
 ) -> Result<SelectorList<SelectorImpl>, ParseError<'i>> {
     let mut ns = Namespaces::default();
     ns.prefixes
diff --git a/tests/unit/style/str.rs b/tests/unit/style/str.rs
index 9445ce167cc..6730bc21672 100644
--- a/tests/unit/style/str.rs
+++ b/tests/unit/style/str.rs
@@ -17,7 +17,7 @@ pub fn split_html_space_chars_whitespace() {
 #[test]
 pub fn test_str_join_empty() {
     let slice: [&str; 0] = [];
-    let actual = str_join(&slice, "-");
+    let actual = str_join(slice, "-");
     let expected = "";
     assert_eq!(actual, expected);
 }
@@ -25,7 +25,7 @@ pub fn test_str_join_empty() {
 #[test]
 pub fn test_str_join_one() {
     let slice = ["alpha"];
-    let actual = str_join(&slice, "-");
+    let actual = str_join(slice, "-");
     let expected = "alpha";
     assert_eq!(actual, expected);
 }
@@ -33,7 +33,7 @@ pub fn test_str_join_one() {
 #[test]
 pub fn test_str_join_many() {
     let slice = ["", "alpha", "", "beta", "gamma", ""];
-    let actual = str_join(&slice, "-");
+    let actual = str_join(slice, "-");
     let expected = "-alpha--beta-gamma-";
     assert_eq!(actual, expected);
 }
diff --git a/tests/unit/style/stylist.rs b/tests/unit/style/stylist.rs
index 043774403e7..a1f2701411d 100644
--- a/tests/unit/style/stylist.rs
+++ b/tests/unit/style/stylist.rs
@@ -35,7 +35,7 @@ fn get_mock_rules(css_selectors: &[&str]) -> (Vec<Vec<Rule>>, SharedRwLock) {
                         .unwrap();
 
                 let locked = Arc::new(shared_lock.wrap(StyleRule {
-                    selectors: selectors,
+                    selectors,
                     block: Arc::new(shared_lock.wrap(PropertyDeclarationBlock::with_one(
                         PropertyDeclaration::Display(longhands::display::SpecifiedValue::Block),
                         Importance::Normal,
@@ -75,7 +75,7 @@ fn parse_selectors(selectors: &[&str]) -> Vec<Selector<SelectorImpl>> {
                 .unwrap()
                 .0
                 .into_iter()
-                .nth(0)
+                .next()
                 .unwrap()
         })
         .collect()
@@ -130,7 +130,7 @@ fn test_revalidation_selectors() {
         "p:first-child span",
     ])
     .into_iter()
-    .filter(|s| needs_revalidation_for_testing(&s))
+    .filter(needs_revalidation_for_testing)
     .collect::<Vec<_>>();
 
     let reference = parse_selectors(&[