diff --git a/cow/__init__.py b/cow/__init__.py
index 8f25657..87a2594 100644
--- a/cow/__init__.py
+++ b/cow/__init__.py
@@ -1,4 +1,4 @@
 #!/usr/bin/env python
 # -*- coding: utf-8 -*-
 
-__version__ = '0.7.0'
+__version__ = '0.7.1'
diff --git a/cow/server.py b/cow/server.py
index e456dd0..b4096af 100644
--- a/cow/server.py
+++ b/cow/server.py
@@ -96,6 +96,8 @@ def plugin_before_end(self, *args, **kw):
     def initialize_assets(self):
         assets = self.get_assets()
         self.application.assets = assets
+        if not assets:
+            return
 
         self.application.assets_environment = Environment(
             directory=self.static_path,