diff --git a/setup.py b/setup.py
--- a/setup.py
+++ b/setup.py
@@ -53,7 +53,7 @@ requirements = [
     "SQLAlchemy >= 1.1, < 1.4",
     "Mako >= 0.9.1, < 1.1",
     "Pygments >= 2.2.0, < 2.5",
-    "Whoosh >= 2.5.0, < 2.8",
+    "Whoosh >= 2.7.1, < 2.8",
     "celery >= 3.1, < 4.0", # TODO: celery 4 doesn't work
     "Babel >= 1.3, < 2.8",
     "python-dateutil >= 2.1.0, < 2.9",