diff --git a/components/plugins/lints/unrooted_must_root.rs b/components/plugins/lints/unrooted_must_root.rs
index d6ecacc25dd..5b6e16c99e9 100644
--- a/components/plugins/lints/unrooted_must_root.rs
+++ b/components/plugins/lints/unrooted_must_root.rs
@@ -129,17 +129,18 @@ impl LateLintPass for UnrootedPass {
             visit::FnKind::Closure => return,
         };
 
-        if !in_new_function {
-            for arg in &decl.inputs {
-                cx.tcx.ast_ty_to_ty_cache.borrow().get(&arg.ty.id).map(|t| {
-                    if is_unrooted_ty(cx, t, false) {
-                        if in_derive_expn(cx, span) {
-                            return;
-                        }
-                        cx.span_lint(UNROOTED_MUST_ROOT, arg.ty.span, "Type must be rooted")
+        for arg in &decl.inputs {
+            cx.tcx.ast_ty_to_ty_cache.borrow().get(&arg.ty.id).map(|t| {
+                if is_unrooted_ty(cx, t, false) {
+                    if in_derive_expn(cx, span) {
+                        return;
                     }
-                });
-            }
+                    cx.span_lint(UNROOTED_MUST_ROOT, arg.ty.span, "Type must be rooted")
+                }
+            });
+        }
+
+        if !in_new_function {
             if let hir::Return(ref ty) = decl.output {
                 cx.tcx.ast_ty_to_ty_cache.borrow().get(&ty.id).map(|t| {
                     if is_unrooted_ty(cx, t, false) {
diff --git a/components/script/dom/filelist.rs b/components/script/dom/filelist.rs
index 57542b0a51d..d695ac8f43a 100644
--- a/components/script/dom/filelist.rs
+++ b/components/script/dom/filelist.rs
@@ -18,6 +18,7 @@ pub struct FileList {
 }
 
 impl FileList {
+    #[allow(unrooted_must_root)]
     fn new_inherited(files: Vec<JS<File>>) -> FileList {
         FileList {
             reflector_: Reflector::new(),
@@ -25,6 +26,7 @@ impl FileList {
         }
     }
 
+    #[allow(unrooted_must_root)]
     pub fn new(window: &Window, files: Vec<JS<File>>) -> Root<FileList> {
         reflect_dom_object(box FileList::new_inherited(files), GlobalRef::Window(window), FileListBinding::Wrap)
     }
diff --git a/components/script/dom/htmlcollection.rs b/components/script/dom/htmlcollection.rs
index dda2bd9b3b8..4ddc0fef6dd 100644
--- a/components/script/dom/htmlcollection.rs
+++ b/components/script/dom/htmlcollection.rs
@@ -32,6 +32,7 @@ pub struct HTMLCollection {
 }
 
 impl HTMLCollection {
+    #[allow(unrooted_must_root)]
     fn new_inherited(collection: Collection) -> HTMLCollection {
         HTMLCollection {
             reflector_: Reflector::new(),
@@ -39,6 +40,7 @@ impl HTMLCollection {
         }
     }
 
+    #[allow(unrooted_must_root)]
     pub fn new(window: &Window, collection: Collection) -> Root<HTMLCollection> {
         reflect_dom_object(box HTMLCollection::new_inherited(collection),
                            GlobalRef::Window(window), HTMLCollectionBinding::Wrap)
diff --git a/components/script/dom/nodelist.rs b/components/script/dom/nodelist.rs
index 2ed127dd2dc..490df73bd56 100644
--- a/components/script/dom/nodelist.rs
+++ b/components/script/dom/nodelist.rs
@@ -27,6 +27,7 @@ pub struct NodeList {
 }
 
 impl NodeList {
+    #[allow(unrooted_must_root)]
     fn new_inherited(list_type: NodeListType) -> NodeList {
         NodeList {
             reflector_: Reflector::new(),
@@ -34,6 +35,7 @@ impl NodeList {
         }
     }
 
+    #[allow(unrooted_must_root)]
     pub fn new(window: &Window,
                list_type: NodeListType) -> Root<NodeList> {
         reflect_dom_object(box NodeList::new_inherited(list_type),