diff --git a/product/PortalTransforms/Transform.py b/product/PortalTransforms/Transform.py
index 00e2699232a49a58a6e5262eabcb3f129a7b279a..1c62adc6a27f509efd025125ed0ea40c83fcec9b 100644
--- a/product/PortalTransforms/Transform.py
+++ b/product/PortalTransforms/Transform.py
@@ -183,7 +183,7 @@ class Transform(SimpleItem):
             self._load_transform()
         return self._v_transform.__doc__
 
-    security.declarePublic('get_documentation')
+    security.declarePrivate('convert')
     def convert(self, *args, **kwargs):
         """ return apply the transform and return the result """
         if not hasattr(self, '_v_transform'):
diff --git a/product/PortalTransforms/TransformEngine.py b/product/PortalTransforms/TransformEngine.py
index 3e41abd76f87cefe3bddc10628551e32efa0bb95..0da457c9d80f521f71c4ca246083bf89ae74f545 100644
--- a/product/PortalTransforms/TransformEngine.py
+++ b/product/PortalTransforms/TransformEngine.py
@@ -76,6 +76,7 @@ class TransformTool(UniqueObject, ActionProviderBase, Folder):
 
     # mimetype oriented conversions (iengine interface)
 
+    security.declarePrivate('unregisterTransform')
     def unregisterTransform(self, name):
         """ unregister a transform
         name is the name of a registered transform
@@ -85,6 +86,7 @@ class TransformTool(UniqueObject, ActionProviderBase, Folder):
             self._delObject(name)
 
 
+    security.declarePrivate('convertTo')
     def convertTo(self, target_mimetype, orig, data=None, object=None,
                   usedby=None, context=None, **kwargs):
         """Convert orig to a given mimetype
@@ -587,6 +589,7 @@ class TransformTool(UniqueObject, ActionProviderBase, Folder):
 
     # mimetype oriented conversions (iengine interface)
 
+    security.declarePrivate('registerTransform')
     def registerTransform(self, transform):
         """register a new transform