diff --git a/components/script/dom/element.rs b/components/script/dom/element.rs
index 594c63bbab6..f28070a7bf7 100644
--- a/components/script/dom/element.rs
+++ b/components/script/dom/element.rs
@@ -4146,7 +4146,7 @@ impl Element {
     // https://html.spec.whatwg.org/multipage/#language
     pub fn get_lang(&self) -> String {
         self.upcast::<Node>()
-            .inclusive_ancestors(ShadowIncluding::No)
+            .inclusive_ancestors(ShadowIncluding::Yes)
             .filter_map(|node| {
                 node.downcast::<Element>().and_then(|el| {
                     el.get_attribute(&ns!(xml), &local_name!("lang"))
diff --git a/tests/wpt/meta/html/dom/elements/global-attributes/lang-attribute-shadow.window.js.ini b/tests/wpt/meta/html/dom/elements/global-attributes/lang-attribute-shadow.window.js.ini
deleted file mode 100644
index 69d3423ce87..00000000000
--- a/tests/wpt/meta/html/dom/elements/global-attributes/lang-attribute-shadow.window.js.ini
+++ /dev/null
@@ -1,9 +0,0 @@
-[lang-attribute-shadow.window.html]
-  [lang on slot inherits from shadow host]
-    expected: FAIL
-
-  [lang only on host]
-    expected: FAIL
-
-  [lang on host and slotted element]
-    expected: FAIL