diff --git a/core/api/src/main/java/org/onosproject/net/PortNumber.java b/core/api/src/main/java/org/onosproject/net/PortNumber.java
index dd77d0c..b80c46f 100644
--- a/core/api/src/main/java/org/onosproject/net/PortNumber.java
+++ b/core/api/src/main/java/org/onosproject/net/PortNumber.java
@@ -132,7 +132,7 @@
     /**
      * Returns the port number representing the specified string value.
      *
-     * @param string port number as string value
+     * @param string port number as decimal, hexadecimal, or octal number string
      * @return port number
      */
     public static PortNumber portNumber(String string) {