diff --git a/spec/memo_wise_spec.rb b/spec/memo_wise_spec.rb
index 6e73d3a..a2355a1 100644
--- a/spec/memo_wise_spec.rb
+++ b/spec/memo_wise_spec.rb
@@ -365,18 +365,32 @@ RSpec.describe MemoWise do
           end
         end
 
+        let(:nested_module_with_initializer) do
+          Module.new do
+            include Module3
+            def initialize(*); end
+          end
+        end
+
         let(:klass_with_module_with_initializer) do
           Class.new do
             include Module3
           end
         end
 
+        let(:klass_with_nested_module_with_initializer) do
+          Class.new do
+            include Module4
+          end
+        end
+
         let(:instance) { klass.new }
 
         before(:each) do
           stub_const("Module1", module1)
           stub_const("Module2", module2)
           stub_const("Module3", module_with_initializer)
+          stub_const("Module4", nested_module_with_initializer)
         end
 
         it "memoizes inherited methods separately" do
@@ -402,6 +416,14 @@ RSpec.describe MemoWise do
           expect(instance.module1_method_counter).to eq(1)
         end
 
+        it "can memoize klass with nested module with initializer" do
+          instance = klass_with_nested_module_with_initializer.new(true)
+          expect { instance.module1_method }.not_to raise_error
+
+          expect(Array.new(4) { instance.module1_method }).to all eq("module1_method")
+          expect(instance.module1_method_counter).to eq(1)
+        end
+
         it "can reset klass with initializer" do
           instance = klass_with_initializer.new(true)
           expect { instance.reset_memo_wise }.not_to raise_error
@@ -411,6 +433,11 @@ RSpec.describe MemoWise do
           instance = klass_with_module_with_initializer.new(true)
           expect { instance.reset_memo_wise }.not_to raise_error
         end
+
+        it "can reset klass with nested module with initializer" do
+          instance = klass_with_nested_module_with_initializer.new(true)
+          expect { instance.reset_memo_wise }.not_to raise_error
+        end
       end
 
       context "when the class, its superclass, and its module all memoize methods" do

diff --git a/lib/memo_wise.rb b/lib/memo_wise.rb
index e793603..4a5ee2a 100644
--- a/lib/memo_wise.rb
+++ b/lib/memo_wise.rb
@@ -97,10 +97,16 @@ module MemoWise
   private_constant(:CreateMemoWiseStateOnInherited)
 
   module CreateMemoWiseStateOnIncluded
+    module CreateMemoWiseStateOnInitialize
+      class_eval(INITIALIZE_LITERAL, __FILE__, __LINE__ + 1)
+    end
+
     def included(base)
-      base.prepend(Module.new do
-        class_eval(INITIALIZE_LITERAL, __FILE__, __LINE__ + 1)
-      end)
+      if base.is_a?(Class)
+        base.prepend(CreateMemoWiseStateOnInitialize)
+      elsif !base.singleton_class?
+        base.singleton_class.prepend(CreateMemoWiseStateOnIncluded)
+      end
     end
   end
   private_constant(:CreateMemoWiseStateOnIncluded)