From dafebc9a4de03fcd5c31fd038af5c8ccba3d30a2 Mon Sep 17 00:00:00 2001
From: Matthew Tretter <m@tthewwithanm.com>
Date: Fri, 5 Apr 2013 14:11:26 -0400
Subject: [PATCH] Don't call register without spec

---
 imagekit/specs/__init__.py | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/imagekit/specs/__init__.py b/imagekit/specs/__init__.py
index c12acfa..3c65836 100644
--- a/imagekit/specs/__init__.py
+++ b/imagekit/specs/__init__.py
@@ -202,7 +202,9 @@ class SpecHost(object):
 
         """
         self.spec_id = id
-        register.generator(id, self._original_spec)
+
+        if self._original_spec:
+            register.generator(id, self._original_spec)
 
     def get_spec(self, source):
         """