diff --git a/of/ctl/src/main/java/org/onlab/onos/of/controller/impl/internal/SwitchDriverSubHandshakeAlreadyStarted.java b/of/ctl/src/main/java/org/onlab/onos/of/controller/impl/internal/SwitchDriverSubHandshakeAlreadyStarted.java
new file mode 100644
index 0000000..53227aa
--- /dev/null
+++ b/of/ctl/src/main/java/org/onlab/onos/of/controller/impl/internal/SwitchDriverSubHandshakeAlreadyStarted.java
@@ -0,0 +1,14 @@
+package org.onlab.onos.of.controller.impl.internal;
+
+/**
+ * Thrown when IOFSwitch.startDriverHandshake() is called more than once.
+ *
+ */
+public class SwitchDriverSubHandshakeAlreadyStarted extends
+    SwitchDriverSubHandshakeException {
+    private static final long serialVersionUID = -5491845708752443501L;
+
+    public SwitchDriverSubHandshakeAlreadyStarted() {
+        super();
+    }
+}