diff --git a/core/api/src/main/java/org/onosproject/net/GridType.java b/core/api/src/main/java/org/onosproject/net/GridType.java
index 498b908..1e21fac 100644
--- a/core/api/src/main/java/org/onosproject/net/GridType.java
+++ b/core/api/src/main/java/org/onosproject/net/GridType.java
@@ -25,5 +25,6 @@
 public enum GridType {
     DWDM,               // Dense Wavelength Division Multiplexing
     CWDM,               // Coarse WDM
-    FLEX                // Flex Grid
+    FLEX,               // Flex Grid
+    UNKNOWN             // Unknown
 }