diff --git a/tailbone/forms2/core.py b/tailbone/forms2/core.py
index d3301bdf..95561fed 100644
--- a/tailbone/forms2/core.py
+++ b/tailbone/forms2/core.py
@@ -576,7 +576,11 @@ class Form(object):
             self.enums.pop(key, None)
 
     def set_renderer(self, key, renderer):
-        self.renderers[key] = renderer
+        if renderer is None:
+            if key in self.renderers:
+                del self.renderers[key]
+        else:
+            self.renderers[key] = renderer
 
     def set_widget(self, key, widget):
         self.widgets[key] = widget