Make inner class static
diff --git a/src/main/java/net/onrc/onos/ofcontroller/util/FlowEntryMatch.java b/src/main/java/net/onrc/onos/ofcontroller/util/FlowEntryMatch.java
index a721ff2..fd41d09 100644
--- a/src/main/java/net/onrc/onos/ofcontroller/util/FlowEntryMatch.java
+++ b/src/main/java/net/onrc/onos/ofcontroller/util/FlowEntryMatch.java
@@ -16,7 +16,7 @@
     /**
      * A class for storing a value to match.
      */
-    class Field<T> {
+    static class Field<T> {
 	/**
 	 * Default constructor.
 	 */