diff --git a/src/main/java/io/appium/java_client/remote/AndroidMobileCapabilityType.java b/src/main/java/io/appium/java_client/remote/AndroidMobileCapabilityType.java
index b661e8bc0..0e8b04baa 100644
--- a/src/main/java/io/appium/java_client/remote/AndroidMobileCapabilityType.java
+++ b/src/main/java/io/appium/java_client/remote/AndroidMobileCapabilityType.java
@@ -239,4 +239,9 @@ public interface AndroidMobileCapabilityType extends CapabilityType {
     String ANDROID_SCREENSHOT_PATH = "androidScreenshotPath";
 
     String SELENDROID_PORT = "selendroidPort";
+
+    /**
+     * The port number, which being used by UIAutomator2
+     */
+    String SYSTEM_PORT = "systemPort";
 }