diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 7b67f2a..6140cb0 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -25,6 +25,12 @@ jobs:
             database-password: 'root'
             database-port: '3306'
             docker-compose-file: 'docker-compose.ci.mysql.yml'
+          - ruby-version: '3.3.5'
+            database-adapter: 'postgresql'
+            database-user: 'postgres'
+            database-password: 'postgres'
+            database-port: '5432'
+            docker-compose-file: 'docker-compose.ci.postgresql.yml'
           - ruby-version: 'jruby-9.1.17.0'
             database-adapter: 'mysql2'
             database-user: 'root'
@@ -37,6 +43,12 @@ jobs:
             database-password: 'postgres'
             database-port: '5432'
             docker-compose-file: 'docker-compose.ci.postgresql.yml'
+          - ruby-version: '3.3.5'
+            database-adapter: 'postgresql'
+            database-user: 'postgres'
+            database-password: 'postgres'
+            database-port: '5432'
+            docker-compose-file: 'docker-compose.ci.postgresql.yml'
           - ruby-version: 'jruby-9.1.17.0'
             database-adapter: 'postgresql'
             database-user: 'postgres'
diff --git a/lib/killbill_client/models/resource.rb b/lib/killbill_client/models/resource.rb
index 084571a..70e6ba9 100644
--- a/lib/killbill_client/models/resource.rb
+++ b/lib/killbill_client/models/resource.rb
@@ -174,15 +174,16 @@ def instantiate_record_from_json(resource_class, data)
 
         def attribute(name)
           send('attr_accessor', name.to_sym)
-	  attributes = @json_attributes ||= []
-	  begin
-	    json_attributes.push(name.to_s)
-	  rescue NameError
-	    (class << self; self; end).
-	      send(:define_method, :json_attributes) { attributes }
-	    retry
-	  end
-	end
+          attributes = @json_attributes ||= []
+
+          if respond_to?(:json_attributes, true)
+            json_attributes.push(name.to_s)
+          else
+            (class << self; self; end).
+              send(:define_method, :json_attributes) { attributes }
+            json_attributes.push(name.to_s)
+          end
+        end
 
         def has_many(attr_name, type = nil)
           send("attr_accessor", attr_name.to_sym)