diff --git a/ckan/plugins/core.py b/ckan/plugins/core.py
index 1fee98a10f3..f2ff584a63f 100644
--- a/ckan/plugins/core.py
+++ b/ckan/plugins/core.py
@@ -11,7 +11,7 @@
 from pyutilib.component.core import SingletonPlugin as _pca_SingletonPlugin
 from pyutilib.component.core import Plugin as _pca_Plugin
 
-from ckan.plugins.interfaces import IPluginObserver
+from ckan.plugins.interfaces import IPluginObserver, IGenshiStreamFilter
 
 __all__ = [
     'PluginImplementations', 'implements',
@@ -123,6 +123,10 @@ def load(plugin):
     service.activate()
     for observer_plugin in observers:
         observer_plugin.after_load(service)
+
+    if IGenshiStreamFilter in service.__interfaces__:
+       log.warn("Plugin '%s' is using deprecated interface IGenshiStreamFilter" % plugin)
+
     return service
 
 
diff --git a/doc/writing-extensions.rst b/doc/writing-extensions.rst
index 6dea271e130..0d63f36582f 100644
--- a/doc/writing-extensions.rst
+++ b/doc/writing-extensions.rst
@@ -141,6 +141,7 @@ Here's a list of some of the more commonly used plugin interfaces:
 
 :class:`~ckan.plugins.interfaces.IGenshiStreamFilter`
     Intercept template rendering to modify the output.
+.. warning :: This interface is currently deprecated, use ITemplateHelpers instead.
 
 :class:`~ckan.plugins.interfaces.IResourcePreview`
     Add custom previews. The preview extensions can make use of the resoucre proxy extension, if enabled.