diff --git a/django/template/__init__.py b/django/template/__init__.py
index 6fd8a03250..90fd13e1ce 100644
--- a/django/template/__init__.py
+++ b/django/template/__init__.py
@@ -814,7 +814,7 @@ class Library(object):
             raise InvalidTemplateLibrary, "Unsupported arguments to Library.tag: (%r, %r)", (name, compile_function)
 
     def tag_function(self,func):
-        self.tags[func.__name__] = func
+        self.tags[getattr(func, "_decorated_function", func).__name__] = func
         return func
 
     def filter(self, name=None, filter_func=None):
@@ -838,7 +838,7 @@ class Library(object):
             raise InvalidTemplateLibrary, "Unsupported arguments to Library.filter: (%r, %r)", (name, filter_func)
 
     def filter_function(self, func):
-        self.filters[func.__name__] = func
+        self.filters[getattr(func, "_decorated_function", func).__name__] = func
         return func
 
     def simple_tag(self,func):
@@ -852,9 +852,9 @@ class Library(object):
                 resolved_vars = [resolve_variable(var, context) for var in self.vars_to_resolve]
                 return func(*resolved_vars)
 
-        compile_func = curry(generic_tag_compiler, params, defaults, func.__name__, SimpleNode)
+        compile_func = curry(generic_tag_compiler, params, defaults, getattr(func, "_decorated_function", func).__name__, SimpleNode)
         compile_func.__doc__ = func.__doc__
-        self.tag(func.__name__, compile_func)
+        self.tag(getattr(func, "_decorated_function", func).__name__, compile_func)
         return func
 
     def inclusion_tag(self, file_name, context_class=Context, takes_context=False):
@@ -888,9 +888,9 @@ class Library(object):
                         self.nodelist = t.nodelist
                     return self.nodelist.render(context_class(dict))
 
-            compile_func = curry(generic_tag_compiler, params, defaults, func.__name__, InclusionNode)
+            compile_func = curry(generic_tag_compiler, params, defaults, getattr(func, "_decorated_function", func).__name__, InclusionNode)
             compile_func.__doc__ = func.__doc__
-            self.tag(func.__name__, compile_func)
+            self.tag(getattr(func, "_decorated_function", func).__name__, compile_func)
             return func
         return dec
 
diff --git a/django/template/defaultfilters.py b/django/template/defaultfilters.py
index 9c72201984..b53375b42d 100644
--- a/django/template/defaultfilters.py
+++ b/django/template/defaultfilters.py
@@ -35,10 +35,6 @@ def stringfilter(func):
             args[0] = smart_string(args[0])
         return func(*args, **kwargs)
         
-    # Make sure the internal name is the original function name because this
-    # is the internal name of the filter if passed directly to Library().filter
-    _dec.__name__ = func.__name__
-    
     # Include a reference to the real function (used to check original
     # arguments by the template parser).
     _dec._decorated_function = getattr(func, '_decorated_function', func)