2 files changed, 1 insertions, 4 deletions
diff --git a/actionpack/lib/action_view/template/handlers.rb b/actionpack/lib/action_view/template/handlers.rb
index 67978ada7e..4e22bec6cc 100644
--- a/actionpack/lib/action_view/template/handlers.rb
+++ b/actionpack/lib/action_view/template/handlers.rb
@@ -23,6 +23,7 @@ module ActionView #:nodoc:
       # and should return the rendered template as a String.
       def register_template_handler(extension, handler)
         @@template_handlers[extension.to_sym] = handler
+        @@template_extensions = nil
       end
 
       def template_handler_extensions
diff --git a/actionpack/lib/action_view/template/handlers/erb.rb b/actionpack/lib/action_view/template/handlers/erb.rb
index 323df67c97..19b9112afd 100644
--- a/actionpack/lib/action_view/template/handlers/erb.rb
+++ b/actionpack/lib/action_view/template/handlers/erb.rb
@@ -44,10 +44,6 @@ module ActionView
         class_attribute :erb_trim_mode
         self.erb_trim_mode = '-'
 
-        # Default format used by ERB.
-        class_attribute :default_format
-        self.default_format = Mime::HTML
-
         # Default implementation used.
         class_attribute :erb_implementation
         self.erb_implementation = Erubis