diff --git a/lib/shrine/plugins/activerecord.rb b/lib/shrine/plugins/activerecord.rb
index 76154cdf..4c376f3b 100644
--- a/lib/shrine/plugins/activerecord.rb
+++ b/lib/shrine/plugins/activerecord.rb
@@ -108,12 +108,12 @@ def activerecord_reload
           record.transaction { yield record.clone.reload(lock: true) }
         end
 
-        # Returns true if the data attribute represents a JSON or JSONB column.
+        # Returns true if the data attribute type is JSON or JSONB.
         # Used by the _persistence plugin to determine whether serialization
         # should be skipped.
         def activerecord_hash_attribute?
-          column = record.class.columns_hash[attribute.to_s]
-          column && [:json, :jsonb].include?(column.type)
+          attribute_type = record.class.type_for_attribute(attribute.to_s)
+          attribute_type && [:json, :jsonb].include?(attribute_type.type)
         end
 
         # Returns whether the record is an ActiveRecord model. Used by the
diff --git a/test/plugin/activerecord_test.rb b/test/plugin/activerecord_test.rb
index 8764c24c..8315ca41 100644
--- a/test/plugin/activerecord_test.rb
+++ b/test/plugin/activerecord_test.rb
@@ -13,10 +13,13 @@
       def self.model_name
         ActiveModel::Name.new(self, nil, "User")
       end
+
+      attribute :json_avatar_data, :json
     end
 
-    @user     = user_class.new
-    @attacher = @shrine::Attacher.from_model(@user, :avatar)
+    @user          = user_class.new
+    @attacher      = @shrine::Attacher.from_model(@user, :avatar)
+    @json_attacher = @shrine::Attacher.from_model(@user, :json_avatar)
   end
 
   after do
@@ -271,22 +274,19 @@ def self.model_name
     describe "JSON columns" do
       [:json, :jsonb].each do |type|
         it "handles #{type} type" do
-          # work around Active Record casting assigned values into a string
-          @user.class.send(:attr_accessor, :avatar_data)
+          # redefine attribute type to make :jsonb test
+          @user.class.type_for_attribute("json_avatar_data").class.send(:define_method, :type) { type }
 
-          columns_hash = @user.class.columns_hash.dup # unfreeze
-          columns_hash["avatar_data"] = columns_hash["avatar_data"].dup # unfreeze
-          columns_hash["avatar_data"].singleton_class.send(:define_method, :type) { type }
-          @user.class.instance_variable_set(:@columns_hash, columns_hash)
+          assert_equal @user.class.type_for_attribute("json_avatar_data").type, type
 
-          @attacher.load_model(@user, :avatar)
-          @attacher.attach(fakeio)
+          @json_attacher.load_model(@user, :json_avatar)
+          @json_attacher.attach(fakeio)
 
-          assert_equal @attacher.file.data, @user.avatar_data
+          assert_equal @json_attacher.file.data, @user.json_avatar_data
 
-          @attacher.reload
+          @json_attacher.reload
 
-          assert_equal @attacher.file.data, @user.avatar_data
+          assert_equal @json_attacher.file.data, @user.json_avatar_data
         end
       end
     end