diff --git a/components/script/dom/headers.rs b/components/script/dom/headers.rs
index 25349d83a9c..197a68b7196 100644
--- a/components/script/dom/headers.rs
+++ b/components/script/dom/headers.rs
@@ -290,7 +290,7 @@ impl Headers {
 
     // https://fetch.spec.whatwg.org/#concept-header-extract-mime-type
     pub fn extract_mime_type(&self) -> Vec<u8> {
-        extract_mime_type(&self.header_list.borrow()).unwrap_or(vec![])
+        extract_mime_type(&self.header_list.borrow()).unwrap_or_default()
     }
 
     // https://fetch.spec.whatwg.org/#concept-header-list-sort-and-combine
diff --git a/components/script/dom/htmlformelement.rs b/components/script/dom/htmlformelement.rs
index b4c2b365f21..fb0686b2618 100644
--- a/components/script/dom/htmlformelement.rs
+++ b/components/script/dom/htmlformelement.rs
@@ -654,7 +654,7 @@ impl HTMLFormElement {
     }
 
     // https://html.spec.whatwg.org/multipage/#text/plain-encoding-algorithm
-    fn encode_plaintext(&self, form_data: &mut Vec<FormDatum>) -> String {
+    fn encode_plaintext(&self, form_data: &mut [FormDatum]) -> String {
         // Step 1
         let mut result = String::new();
 
diff --git a/components/script/dom/htmlinputelement.rs b/components/script/dom/htmlinputelement.rs
index 069c31ad806..72a3d6fa7d9 100755
--- a/components/script/dom/htmlinputelement.rs
+++ b/components/script/dom/htmlinputelement.rs
@@ -767,7 +767,7 @@ impl HTMLInputElement {
         first_with_id
             .as_ref()
             .and_then(|el| el.downcast::<HTMLDataListElement>())
-            .map(|el| DomRoot::from_ref(el))
+            .map(DomRoot::from_ref)
     }
 
     // https://html.spec.whatwg.org/multipage/#suffering-from-being-missing