diff --git a/datasette/app.py b/datasette/app.py
index 48cb2f0e..6152af21 100644
--- a/datasette/app.py
+++ b/datasette/app.py
@@ -533,6 +533,7 @@ class Datasette:
     async def render_template(
         self, templates, context=None, request=None, view_name=None
     ):
+        context = context or {}
         if isinstance(templates, Template):
             template = templates
             select_templates = []