diff --git a/external/annotation.py b/external/annotation.py
index 43ede0f..cb25990 100644
--- a/external/annotation.py
+++ b/external/annotation.py
@@ -41,7 +41,7 @@ class AnnotationsElement(Element):
         for k, v in kw.items():
             self[k] = v
 
-    def __call__(self, loader):
+    def execute(self, loader):
         obj = self.parent.object
         dc = IZopeDublinCore(obj, None)
         if dc is not None:
diff --git a/external/base.py b/external/base.py
index f89fe44..7832f64 100644
--- a/external/base.py
+++ b/external/base.py
@@ -80,7 +80,7 @@ class Loader(Base, SetupManager):
 
     def load(self, elements):
         for element in elements:
-            element(self)
+            element.execute(self)
             if element.subElements is not None:
                 self.load(element.subElements)
 
diff --git a/external/element.py b/external/element.py
index 9b24e52..09c0dd1 100644
--- a/external/element.py
+++ b/external/element.py
@@ -69,7 +69,7 @@ class Element(dict):
             self.subElements = []
         self.subElements.append(element)
 
-    def __call__(self, loader):
+    def execute(self, loader):
         pass
 
 
@@ -78,7 +78,7 @@ class ConceptElement(Element):
     elementType = 'concept'
     posArgs = ('name', 'title', 'type')
 
-    def __call__(self, loader):
+    def execute(self, loader):
         type = loader.concepts[self['type']]
         kw = dict((k, v) for k, v in self.items()
                          if k not in self.posArgs)
@@ -97,7 +97,7 @@ class TypeElement(ConceptElement):
             if not isinstance(ti, basestring):
                 self['typeInterface'] = '.'.join((ti.__module__, ti.__name__))
 
-    def __call__(self, loader):
+    def execute(self, loader):
         kw = dict((k, v) for k, v in self.items()
                 if k not in ('name', 'title', 'type', 'typeInterface'))
         ti = self.get('typeInterface')
@@ -137,7 +137,7 @@ class ResourceElement(Element):
         f.write(content)
         f.close()
 
-    def __call__(self, loader):
+    def execute(self, loader):
         type = loader.concepts[self['type']]
         kw = dict((k, v) for k, v in self.items()
                          if k not in self.posArgs)
@@ -156,7 +156,7 @@ class ResourceRelationElement(ChildElement):
 
     elementType = 'resourceRelation'
 
-    def __call__(self, loader):
+    def execute(self, loader):
         loader.assignResource(self['first'], self['second'], self['predicate'])
 
 
@@ -171,7 +171,7 @@ class NodeElement(Element):
         for k, v in kw.items():
             self[k] = v
 
-    def __call__(self, loader):
+    def execute(self, loader):
         type = self['type']
         cont = traverse(loader.views, self['path'])
         target = self.pop('target', None)
diff --git a/external/interfaces.py b/external/interfaces.py
index cb1828d..681a085 100644
--- a/external/interfaces.py
+++ b/external/interfaces.py
@@ -51,7 +51,7 @@ class IElement(Interface):
         """ Add a sub-element, may be called by the extractor during export.
         """
 
-    def __call__(loader):
+    def execute(loader):
         """ Create the object that is specified by the element in the
             context of the loader and return it.
         """
diff --git a/external/pyfunc.py b/external/pyfunc.py
index 8a74091..83a0293 100644
--- a/external/pyfunc.py
+++ b/external/pyfunc.py
@@ -46,6 +46,7 @@ class InputProcessor(dict):
 
     def __init__(self):
         self.elements = []
+        self['__builtins__'] = {}   # security!
 
     def __getitem__(self, key):
         def factory(*args, **kw):