diff --git a/build.gradle b/build.gradle
index a6e1cfc4..e28e1c55 100644
--- a/build.gradle
+++ b/build.gradle
@@ -19,7 +19,7 @@ apply from: "https://raw.githubusercontent.com/gocd/gocd-plugin-gradle-task-help
 
 gocdPlugin {
     id = 'cd.go.artifact.docker.registry'
-    pluginVersion = '1.3.1'
+    pluginVersion = '1.4.0'
     goCdVersion = '20.9.0'
     name = 'Artifact plugin for docker'
     description = 'Plugin allows to push/pull docker image from public or private docker registry'
diff --git a/src/main/java/cd/go/artifact/docker/registry/Constants.java b/src/main/java/cd/go/artifact/docker/registry/Constants.java
index 3438966f..ff9bbd7c 100644
--- a/src/main/java/cd/go/artifact/docker/registry/Constants.java
+++ b/src/main/java/cd/go/artifact/docker/registry/Constants.java
@@ -18,22 +18,19 @@
 
 import com.thoughtworks.go.plugin.api.GoPluginIdentifier;
 
-import static java.util.Arrays.asList;
+import java.util.List;
 
 public interface Constants {
     // The type of this extension
     String EXTENSION_TYPE = "artifact";
 
     // The extension point API version that this plugin understands
-    String OLDER_EXTENSION_API_VERSION = "1.0";
     String EXTENSION_API_VERSION = "2.0";
     String CONSOLE_LOG_PROCESSOR_API_VERSION = "1.0";
 
     // the identifier of this plugin
-    GoPluginIdentifier PLUGIN_IDENTIFIER = new GoPluginIdentifier(EXTENSION_TYPE, asList(OLDER_EXTENSION_API_VERSION, EXTENSION_API_VERSION));
+    GoPluginIdentifier PLUGIN_IDENTIFIER = new GoPluginIdentifier(EXTENSION_TYPE, List.of(EXTENSION_API_VERSION));
 
     // requests that the plugin makes to the server
-    String REQUEST_SERVER_PREFIX = "go.processor";
-    String REQUEST_SERVER_GET_PLUGIN_SETTINGS = REQUEST_SERVER_PREFIX + ".plugin-settings.get";
     String SEND_CONSOLE_LOG = "go.processor.artifact.console-log";
 }