diff --git a/core/api/src/main/java/org/onosproject/net/driver/DefaultDriver.java b/core/api/src/main/java/org/onosproject/net/driver/DefaultDriver.java
index 7ed674b..6ffdbee 100644
--- a/core/api/src/main/java/org/onosproject/net/driver/DefaultDriver.java
+++ b/core/api/src/main/java/org/onosproject/net/driver/DefaultDriver.java
@@ -15,6 +15,7 @@
  */
 package org.onosproject.net.driver;
 
+import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.Lists;
 import com.google.common.collect.Maps;
@@ -65,7 +66,7 @@
                          Map<Class<? extends Behaviour>, Class<? extends Behaviour>> behaviours,
                          Map<String, String> properties) {
         this.name = checkNotNull(name, "Name cannot be null");
-        this.parents = parents == null || parents.isEmpty() ? null : parents;
+        this.parents = parents == null ? ImmutableList.of() : ImmutableList.copyOf(parents);
         this.manufacturer = checkNotNull(manufacturer, "Manufacturer cannot be null");
         this.hwVersion = checkNotNull(hwVersion, "HW version cannot be null");
         this.swVersion = checkNotNull(swVersion, "SW version cannot be null");
@@ -77,6 +78,7 @@
     public Driver merge(Driver other) {
         checkArgument(parents == null || Objects.equals(parent(), other.parent()),
                       "Parent drivers are not the same");
+
         // Merge the behaviours.
         Map<Class<? extends Behaviour>, Class<? extends Behaviour>>
                 behaviours = Maps.newHashMap();
@@ -126,7 +128,7 @@
 
     @Override
     public Driver parent() {
-        return parents == null ? null : parents.get(0);
+        return parents.isEmpty() ? null : parents.get(0);
     }
 
     @Override
diff --git a/core/api/src/main/java/org/onosproject/net/driver/Driver.java b/core/api/src/main/java/org/onosproject/net/driver/Driver.java
index 7af83b4..d8f6f3c 100644
--- a/core/api/src/main/java/org/onosproject/net/driver/Driver.java
+++ b/core/api/src/main/java/org/onosproject/net/driver/Driver.java
@@ -45,12 +45,11 @@
     @Deprecated
     Driver parent();
 
-    // TODO should revise behaviour to return empty List when driver has no parent
     /**
      * Returns all the parent drivers from which this driver inherits behaviours
      * and properties.
      *
-     * @return list of parent drivers; null if driver has no parent
+     * @return list of parent drivers
      */
     List<Driver> parents();
 
diff --git a/core/api/src/test/java/org/onosproject/net/driver/DefaultDriverTest.java b/core/api/src/test/java/org/onosproject/net/driver/DefaultDriverTest.java
index 330ec8b..2062951 100644
--- a/core/api/src/test/java/org/onosproject/net/driver/DefaultDriverTest.java
+++ b/core/api/src/test/java/org/onosproject/net/driver/DefaultDriverTest.java
@@ -41,6 +41,7 @@
                                               ImmutableMap.of("foo", "bar"));
         assertEquals("incorrect name", "foo.bar", ddc.name());
         assertEquals("incorrect parent", ddp, ddc.parent());
+        assertEquals("incorrect empty parent", ImmutableList.of(), ddp.parents());
         assertEquals("incorrect mfr", "Circus", ddc.manufacturer());
         assertEquals("incorrect hw", "lux", ddc.hwVersion());
         assertEquals("incorrect sw", "1.2a", ddc.swVersion());