diff --git a/tests/content/test_document_adoptNode.html b/tests/content/test_document_adoptNode.html
deleted file mode 100644
index 41481b56af7..00000000000
--- a/tests/content/test_document_adoptNode.html
+++ /dev/null
@@ -1,23 +0,0 @@
-<!DOCTYPE html>
-<html>
-    <head>
-        <script src="harness.js"></script>
-    </head>
-    <body>
-        <div id="foo"><div id="bar"></div></div>
-        <script>
-            let foo = document.getElementById("foo");
-            let doc = document.implementation.createHTMLDocument("title");
-
-            is(foo.ownerDocument, document);
-
-            let adopted_foo = doc.adoptNode(foo);
-            is(document.getElementById("foo"), null);
-
-            is(foo, adopted_foo);
-            is(foo.ownerDocument, doc);
-            is(foo.parentNode, null);
-            is(foo.childNodes.length, 1);
-        </script>
-    </body>
-</html>
