diff --git a/spec/memo_wise_spec.rb b/spec/memo_wise_spec.rb
index abe9025d..874c2a6b 100644
--- a/spec/memo_wise_spec.rb
+++ b/spec/memo_wise_spec.rb
@@ -640,7 +640,7 @@ def self.module_method; end
 
         let(:module1) do
           Module.new do
-            prepend MemoWise
+            extend MemoWise
 
             def module1_method_counter
               @module1_method_counter || 0 # rubocop:disable RSpec/InstanceVariable