It's OK for a tag to contain another, identical tag, just not for it to contain itself.

2 files changed, 1 insertions, 4 deletions

diff --git a/TODO b/TODO
index 564659c..e0e4927 100644
--- a/TODO
+++ b/TODO
@@ -1,6 +1,3 @@
-html5lib frequently raises the "cannot insert a tag into itself"
-error, which makes me think there's a bug in the treebuilder.
-
 Tag.insert_before() and Tag.insert_after()
 
 Also, I think you can avoid the variable altogether by having repr
diff --git a/bs4/element.py b/bs4/element.py
index 211621e..8451d7c 100644
--- a/bs4/element.py
+++ b/bs4/element.py
@@ -109,7 +109,7 @@ class PageElement(object):
     _lastRecursiveChild = _last_descendant
 
     def insert(self, position, new_child):
-        if new_child == self:
+        if new_child is self:
             raise ValueError("Cannot insert a tag into itself.")
         if (isinstance(new_child, basestring)
             and not isinstance(new_child, NavigableString)):