diff --git a/lib/rdoc/task.rb b/lib/rdoc/task.rb
index ec7459729a..b4ff3e99c6 100644
--- a/lib/rdoc/task.rb
+++ b/lib/rdoc/task.rb
@@ -316,6 +316,8 @@ end
 # :stopdoc:
 module Rake
 
+  remove_const(:RDocTask) if defined?(RDocTask) # remove deprecated class
+
   ##
   # For backwards compatibility