diff --git a/setup.py b/setup.py
index 0dfc0f7..089d573 100644
--- a/setup.py
+++ b/setup.py
@@ -11,7 +11,7 @@ setup(
     install_requires=[
         'SQLAlchemy>=1.0,<1.4',
         'whoosh>=2.5,<2.7',
-        'markdown==2.4.1',
+        'markdown>=2.4.1,<=2.6.11',
         'construct==2.5.3',
         'six>=1.9.0',
     ],