diff --git a/lib/rdoc/context.rb b/lib/rdoc/context.rb
index c6edfb473c..c688d562c3 100644
--- a/lib/rdoc/context.rb
+++ b/lib/rdoc/context.rb
@@ -710,7 +710,7 @@ def display(method_attr) # :nodoc:
   # This method exists to make it easy to work with Context subclasses that
   # aren't part of RDoc.
 
-  def each_ancestor # :nodoc:
+  def each_ancestor(&_) # :nodoc:
   end
 
   ##