diff --git a/src/main/java/net/onrc/onos/core/flowprogrammer/FlowPusher.java b/src/main/java/net/onrc/onos/core/flowprogrammer/FlowPusher.java
index 3f5326e..48b2a60 100644
--- a/src/main/java/net/onrc/onos/core/flowprogrammer/FlowPusher.java
+++ b/src/main/java/net/onrc/onos/core/flowprogrammer/FlowPusher.java
@@ -113,7 +113,7 @@
      *
      * @author Naoki Shiota
      */
-    private class SwitchQueue {
+    private static class SwitchQueue {
         List<Queue<SwitchQueueEntry>> rawQueues;
         QueueState state;