diff --git a/lib/rdoc/code_object/mixin.rb b/lib/rdoc/code_object/mixin.rb
index fa8faefc15..2e69987a39 100644
--- a/lib/rdoc/code_object/mixin.rb
+++ b/lib/rdoc/code_object/mixin.rb
@@ -55,6 +55,12 @@ def inspect # :nodoc:
     ]
   end
 
+  def module
+    return @memoized_module if instance_variable_defined?(:@memoized_module)
+
+    @memoized_module = lookup_module
+  end
+
   ##
   # Attempts to locate the included module object.  Returns the name if not
   # known.
@@ -72,7 +78,7 @@ def inspect # :nodoc:
   #
   # As of the beginning of October, 2011, no gem includes nonexistent modules.
 
-  def module
+  def lookup_module
     return @module if @module
 
     # search the current context