diff --git a/rake/CHANGES b/rake/CHANGES
index 8765cabd9..3ea552a54 100644
--- a/rake/CHANGES
+++ b/rake/CHANGES
@@ -3,6 +3,8 @@
 == Pre-Version 0.5.2
 
 * Added support for importing Rakefile and other dependencies.
+* Fixed bug so that now rules can chain off of existing tasks as well
+  as existing files.
 
 == Version 0.5.1
 
diff --git a/rake/lib/rake.rb b/rake/lib/rake.rb
index 8b463c802..e7f9c9e76 100755
--- a/rake/lib/rake.rb
+++ b/rake/lib/rake.rb
@@ -303,7 +303,7 @@ def enhance_with_matching_rule(task_name, level=0)
           else
             fail "Don't know how to handle rule dependent: #{ext.inspect}"
           end
-          if File.exist?(source) || TASKS.has_key?(source)
+          if File.exist?(source) || Task.task_defined?(source)
             task = FileTask.define_task({task_name => [source]}, &block)
             task.source = source
             return task