diff --git a/components/script/dom/bindings/str.rs b/components/script/dom/bindings/str.rs
index 850277f596eb..021d154191ac 100644
--- a/components/script/dom/bindings/str.rs
+++ b/components/script/dom/bindings/str.rs
@@ -49,12 +49,6 @@ impl ByteString {
         ByteString::new(self.0.to_ascii_lowercase())
     }
 
-    /// Returns whether `self` is a `token`, as defined by
-    /// [RFC 2616](http://tools.ietf.org/html/rfc2616#page-17).
-    pub fn is_token(&self) -> bool {
-        is_token(&self.0)
-    }
-
     /// Returns whether `self` is a `field-value`, as defined by
     /// [RFC 2616](http://tools.ietf.org/html/rfc2616#page-32).
     pub fn is_field_value(&self) -> bool {
diff --git a/components/script/dom/xmlhttprequest.rs b/components/script/dom/xmlhttprequest.rs
index 749de9ac29be..947835f11b99 100644
--- a/components/script/dom/xmlhttprequest.rs
+++ b/components/script/dom/xmlhttprequest.rs
@@ -21,7 +21,7 @@ use dom::bindings::js::{JS, MutHeapJSVal, MutNullableHeap};
 use dom::bindings::js::{Root, RootedReference};
 use dom::bindings::refcounted::Trusted;
 use dom::bindings::reflector::{Reflectable, reflect_dom_object};
-use dom::bindings::str::{ByteString, USVString};
+use dom::bindings::str::{ByteString, USVString, is_token};
 use dom::blob::Blob;
 use dom::document::DocumentSource;
 use dom::document::{Document, IsHTMLDocument};
@@ -345,7 +345,7 @@ impl XMLHttpRequestMethods for XMLHttpRequest {
             Some(Method::Extension(ref t)) if &**t == "TRACK" => Err(Error::Security),
             Some(parsed_method) => {
                 // Step 3
-                if !method.is_token() {
+                if !is_token(&method) {
                     return Err(Error::Syntax)
                 }
 
@@ -413,7 +413,7 @@ impl XMLHttpRequestMethods for XMLHttpRequest {
         }
         // FIXME(#9548): Step 3. Normalize value
         // Step 4
-        if !name.is_token() || !value.is_field_value() {
+        if !is_token(&name) || !value.is_field_value() {
             return Err(Error::Syntax);
         }
         let name_lower = name.to_lower();