diff --git a/html5lib/html5parser.py b/html5lib/html5parser.py
index 9fb038b7..4c2d4c75 100644
--- a/html5lib/html5parser.py
+++ b/html5lib/html5parser.py
@@ -115,6 +115,9 @@ def __init__(self, tree=None, strict=False, namespaceHTMLElements=True, debug=Fa
 
         if tree is None:
             tree = treebuilders.getTreeBuilder("etree")
+        elif isinstance(tree, str):
+            tree = treebuilders.getTreeBuilder(tree)
+
         self.tree = tree(namespaceHTMLElements)
         self.errors = []