diff --git a/src/main/scala/scala/xml/NamespaceBinding.scala b/src/main/scala/scala/xml/NamespaceBinding.scala
index 8409c41e1..cb97c1d06 100644
--- a/src/main/scala/scala/xml/NamespaceBinding.scala
+++ b/src/main/scala/scala/xml/NamespaceBinding.scala
@@ -73,7 +73,7 @@ case class NamespaceBinding(prefix: String, uri: String, parent: NamespaceBindin
   }
 
   private def doBuildString(sb: StringBuilder, stop: NamespaceBinding) {
-    if ((this == null) || (this eq stop)) return // contains?
+    if (List(null, stop, TopScope).contains(this)) return
 
     val s = " xmlns%s=\"%s\"".format(
       (if (prefix != null) ":" + prefix else ""),
diff --git a/src/test/scala/scala/xml/XMLTest.scala b/src/test/scala/scala/xml/XMLTest.scala
index 01431baf1..ff59de52b 100644
--- a/src/test/scala/scala/xml/XMLTest.scala
+++ b/src/test/scala/scala/xml/XMLTest.scala
@@ -162,6 +162,15 @@ class XMLTest {
     }
   }
 
+  @UnitTest
+  def namespacesWithNestedXmls: Unit = {
+    val foo = <f:foo xmlns:f="fooUrl"></f:foo>
+    val bar = <b:bar xmlns:b="barUrl">{foo}</b:bar>
+    val expected = """<b:bar xmlns:b="barUrl"><f:foo xmlns:f="fooUrl"></f:foo></b:bar>"""
+    val actual = bar.toString
+    assertEquals(expected, actual)
+  }
+
   @UnitTest
   def validationOfElements: Unit = {
     val vtor = new scala.xml.dtd.ElementValidator();