diff --git a/components/script/dom/bindings/codegen/CodegenRust.py b/components/script/dom/bindings/codegen/CodegenRust.py
index 486758182d2..9644f589072 100644
--- a/components/script/dom/bindings/codegen/CodegenRust.py
+++ b/components/script/dom/bindings/codegen/CodegenRust.py
@@ -4658,7 +4658,7 @@ class CGProxyNamedOperation(CGProxySpecialOperation):
     def define(self):
         # Our first argument is the id we're getting.
         argName = self.arguments[0].identifier.name
-        return ("let %s = jsid_to_str(cx, id);\n"
+        return ("let %s = string_jsid_to_string(cx, id);\n"
                 "let this = UnwrapProxy(proxy);\n"
                 "let this = &*this;\n" % argName +
                 CGProxySpecialOperation.define(self))
@@ -5528,13 +5528,13 @@ def generate_imports(config, cgthings, descriptors, callbacks=None, dictionaries
         'dom::bindings::conversions::StringificationBehavior',
         'dom::bindings::conversions::ToJSValConvertible',
         'dom::bindings::conversions::is_array_like',
-        'dom::bindings::conversions::jsid_to_str',
         'dom::bindings::conversions::native_from_handlevalue',
         'dom::bindings::conversions::native_from_object',
         'dom::bindings::conversions::private_from_object',
         'dom::bindings::conversions::root_from_handleobject',
         'dom::bindings::conversions::root_from_handlevalue',
         'dom::bindings::conversions::root_from_object',
+        'dom::bindings::conversions::string_jsid_to_string',
         'dom::bindings::codegen::PrototypeList',
         'dom::bindings::codegen::RegisterBindings',
         'dom::bindings::codegen::UnionTypes',
diff --git a/components/script/dom/bindings/conversions.rs b/components/script/dom/bindings/conversions.rs
index 113a9d279d5..bb29b9904a1 100644
--- a/components/script/dom/bindings/conversions.rs
+++ b/components/script/dom/bindings/conversions.rs
@@ -115,9 +115,14 @@ impl <T: Reflectable + IDLInterface> FromJSValConvertible for Root<T> {
     }
 }
 
-/// Convert the given `jsid` to a `DOMString`. Fails if the `jsid` is not a
-/// string, or if the string does not contain valid UTF-16.
-pub fn jsid_to_str(cx: *mut JSContext, id: HandleId) -> DOMString {
+/// Convert `id` to a `DOMString`, assuming it is string-valued.
+///
+/// Handling of invalid UTF-16 in strings depends on the relevant option.
+///
+/// # Panics
+///
+/// Panics if `id` is not string-valued.
+pub fn string_jsid_to_string(cx: *mut JSContext, id: HandleId) -> DOMString {
     unsafe {
         assert!(RUST_JSID_IS_STRING(id));
         jsstring_to_str(cx, RUST_JSID_TO_STRING(id))