diff --git a/genericadmin/admin.py b/genericadmin/admin.py
index f684637..9ab5b2e 100644
--- a/genericadmin/admin.py
+++ b/genericadmin/admin.py
@@ -37,6 +37,9 @@ def __init__(self, model, admin_site):
             media = []
         media.append(JS_PATH + 'genericadmin.js')
         self.Media.js = tuple(media)
+        
+        self.content_type_whitelist = [s.lower() for s in self.content_type_whitelist]
+        self.content_type_blacklist = [s.lower() for s in self.content_type_blacklist]        
             
         super(BaseGenericModelAdmin, self).__init__(model, admin_site)
 
@@ -152,4 +155,4 @@ class TabularInlineWithGeneric(BaseGenericModelAdmin, admin.TabularInline):
 
 
 class StackedInlineWithGeneric(BaseGenericModelAdmin, admin.StackedInline):
-    """"Normal stacked inline with a generic relation"""
\ No newline at end of file
+    """"Normal stacked inline with a generic relation"""