diff --git a/spec/dummy/app/models/configuration.rb b/spec/dummy/app/models/configuration.rb
index 98ffdee..49c14a9 100644
--- a/spec/dummy/app/models/configuration.rb
+++ b/spec/dummy/app/models/configuration.rb
@@ -3,10 +3,17 @@
 class Configuration
   include StoreModel::Model
 
+  class Encrypted < ActiveModel::Type::Value
+    def cast_value(value)
+      "=#{value}=" if value
+    end
+  end
+
   attribute :color, :string
   attribute :model, :string
   attribute :active, :boolean
   attribute :disabled_at, :datetime
+  attribute :encrypted_serial, Encrypted.new
 
   alias_attribute :enabled, :active
 
diff --git a/spec/store_model/model_spec.rb b/spec/store_model/model_spec.rb
index b5e1a35..761bcf4 100644
--- a/spec/store_model/model_spec.rb
+++ b/spec/store_model/model_spec.rb
@@ -8,13 +8,15 @@
       color: "red",
       model: nil,
       active: false,
-      disabled_at: Time.new(2019, 2, 10, 12)
+      disabled_at: Time.new(2019, 2, 10, 12),
+      encrypted_serial: nil
     }
   end
 
   describe "#initialize" do
+    subject { Configuration.new(attributes) }
+
     context "when symbolized hash is passed" do
-      subject { Configuration.new(attributes) }
 
       it("assigns attributes") { is_expected.to have_attributes(attributes) }
     end
@@ -24,6 +26,20 @@
 
       it("assigns attributes") { is_expected.to have_attributes(attributes) }
     end
+
+    context "when attributes contain a field with a custom type" do
+      let(:attributes) do
+        {
+          color: "red",
+          model: nil,
+          active: false,
+          disabled_at: Time.new(2019, 2, 10, 12),
+          encrypted_serial: "111-222"
+        }
+      end
+
+      it("assigns attributes") { is_expected.to have_attributes(attributes.merge(encrypted_serial: "=111-222=")) }
+    end
   end
 
   describe "#as_json" do
@@ -52,7 +68,7 @@
     it "prints description" do
       expect(subject).to eq(
         "#<Configuration color: red, model: nil, active: false, " \
-        "disabled_at: #{attributes[:disabled_at]}>"
+        "disabled_at: #{attributes[:disabled_at]}, encrypted_serial: nil>"
       )
     end
   end
diff --git a/spec/store_model/types/one_polymorphic_spec.rb b/spec/store_model/types/one_polymorphic_spec.rb
index fe6f8d4..d0d34f2 100644
--- a/spec/store_model/types/one_polymorphic_spec.rb
+++ b/spec/store_model/types/one_polymorphic_spec.rb
@@ -10,7 +10,8 @@
       color: "red",
       model: nil,
       active: false,
-      disabled_at: Time.new(2019, 2, 22, 12, 30)
+      disabled_at: Time.new(2019, 2, 22, 12, 30),
+      encrypted_serial: nil
     }
   end
 
diff --git a/spec/store_model/types/one_spec.rb b/spec/store_model/types/one_spec.rb
index 4d541e4..a9fd265 100644
--- a/spec/store_model/types/one_spec.rb
+++ b/spec/store_model/types/one_spec.rb
@@ -10,7 +10,8 @@
       color: "red",
       model: nil,
       active: false,
-      disabled_at: Time.new(2019, 2, 22, 12, 30)
+      disabled_at: Time.new(2019, 2, 22, 12, 30),
+      encrypted_serial: nil
     }
   end