diff --git a/lib/kong/plugin.rb b/lib/kong/plugin.rb
index 8d26f97..9f50baf 100644
--- a/lib/kong/plugin.rb
+++ b/lib/kong/plugin.rb
@@ -14,7 +14,13 @@ def create
       super
     end
 
-    # update resource
+    # Create or update resource
+    def create_or_update
+      flatten_config
+      super
+    end
+
+    # Update resource
     def update
       flatten_config
       super
diff --git a/spec/kong/plugin_spec.rb b/spec/kong/plugin_spec.rb
index 3119773..9a55910 100644
--- a/spec/kong/plugin_spec.rb
+++ b/spec/kong/plugin_spec.rb
@@ -42,6 +42,24 @@
     end
   end
 
+  describe '#create_or_update' do
+    it 'transforms config keys to config.key format' do
+      headers = { 'Content-Type' => 'application/json' }
+      attributes = { 'api_id' => ':api_id', 'config.anonymous' => '12345' }
+      expect(Kong::Client.instance).to receive(:put).with('/apis/:api_id/plugins/', attributes, nil, headers).and_return(attributes)
+      subject = described_class.new({ api_id: ':api_id', config: { 'anonymous' => '12345' } })
+      subject.create_or_update
+    end
+
+    it 'transforms nested config keys to config.key format' do
+      headers = { 'Content-Type' => 'application/json' }
+      attributes = { 'api_id' => ':api_id', 'config.anonymous' => '12345', 'config.first.second' => '1' }
+      expect(Kong::Client.instance).to receive(:put).with('/apis/:api_id/plugins/', attributes, nil, headers).and_return(attributes)
+      subject = described_class.new({ api_id: ':api_id', config: { 'anonymous' => '12345', 'first' => { 'second' => '1' } } })
+      subject.create_or_update
+    end
+  end
+
   describe '#update' do
     it 'transforms config keys to config.key format' do
       headers = { 'Content-Type' => 'application/json' }