diff --git a/core/api/src/main/java/org/onlab/onos/net/flow/DefaultTrafficSelector.java b/core/api/src/main/java/org/onlab/onos/net/flow/DefaultTrafficSelector.java
index 960eb02..352f604 100644
--- a/core/api/src/main/java/org/onlab/onos/net/flow/DefaultTrafficSelector.java
+++ b/core/api/src/main/java/org/onlab/onos/net/flow/DefaultTrafficSelector.java
@@ -188,7 +188,7 @@
         }
 
         @Override
-        public Builder matchOpticalSignalType(Byte signalType) {
+        public Builder matchOpticalSignalType(Short signalType) {
             return add(Criteria.matchOpticalSignalType(signalType));
 
         }
diff --git a/core/api/src/main/java/org/onlab/onos/net/flow/TrafficSelector.java b/core/api/src/main/java/org/onlab/onos/net/flow/TrafficSelector.java
index aaf0ece..dd8e2ae 100644
--- a/core/api/src/main/java/org/onlab/onos/net/flow/TrafficSelector.java
+++ b/core/api/src/main/java/org/onlab/onos/net/flow/TrafficSelector.java
@@ -147,7 +147,7 @@
          * @param signalType
          * @return a selection builder
          */
-        public Builder matchOpticalSignalType(Byte signalType);
+        public Builder matchOpticalSignalType(Short signalType);
 
         /**
          * Builds an immutable traffic selector.
diff --git a/core/api/src/main/java/org/onlab/onos/net/flow/criteria/Criteria.java b/core/api/src/main/java/org/onlab/onos/net/flow/criteria/Criteria.java
index aba5680..a1ac5f8 100644
--- a/core/api/src/main/java/org/onlab/onos/net/flow/criteria/Criteria.java
+++ b/core/api/src/main/java/org/onlab/onos/net/flow/criteria/Criteria.java
@@ -161,11 +161,11 @@
     /**
      * Creates a match on lambda field using the specified value.
      *
-     * @param lambda
+     * @param sigType
      * @return match criterion
      */
-    public static Criterion matchOpticalSignalType(Byte lambda) {
-        return new OpticalSignalTypeCriterion(lambda, Type.OCH_SIGTYPE);
+    public static Criterion matchOpticalSignalType(Short sigType) {
+        return new OpticalSignalTypeCriterion(sigType, Type.OCH_SIGTYPE);
     }
 
 
@@ -587,10 +587,10 @@
 
     public static final class OpticalSignalTypeCriterion implements Criterion {
 
-        private final byte signalType;
+        private final Short signalType;
         private final Type type;
 
-        public OpticalSignalTypeCriterion(byte signalType, Type type) {
+        public OpticalSignalTypeCriterion(Short signalType, Type type) {
             this.signalType = signalType;
             this.type = type;
         }
@@ -600,7 +600,7 @@
             return this.type;
         }
 
-        public Byte signalType() {
+        public Short signalType() {
             return this.signalType;
         }