diff --git a/core/api/src/main/java/org/onlab/onos/net/flow/instructions/Instruction.java b/core/api/src/main/java/org/onlab/onos/net/flow/instructions/Instruction.java
index a22d2cd..8c41a04 100644
--- a/core/api/src/main/java/org/onlab/onos/net/flow/instructions/Instruction.java
+++ b/core/api/src/main/java/org/onlab/onos/net/flow/instructions/Instruction.java
@@ -5,7 +5,7 @@
  */
 public interface Instruction {
 
-    interface SubType {}
+    interface SubType { }
 
     public enum NoneSubType implements SubType {
         NONE;