diff --git a/requirements.txt b/requirements.txt
index ddd95719..1c716ff4 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,6 +1,6 @@
 ordereddict
 six
-html5lib>=0.999
+html5lib>=0.999,<0.99999999
 
 # Requirements to run the test suite:
 nose