diff --git a/core/api/src/main/java/org/onosproject/ui/model/topo/UiTopoLayoutId.java b/core/api/src/main/java/org/onosproject/ui/model/topo/UiTopoLayoutId.java
index 52056e8..12e57f5 100644
--- a/core/api/src/main/java/org/onosproject/ui/model/topo/UiTopoLayoutId.java
+++ b/core/api/src/main/java/org/onosproject/ui/model/topo/UiTopoLayoutId.java
@@ -23,7 +23,7 @@
  */
 public final class UiTopoLayoutId extends Identifier<String> {
 
-    private static final String DEFAULT_STR = "_default_";
+    private static final String DEFAULT_STR = "root";
 
     /**
      * Default topology layout identifier.
diff --git a/core/api/src/test/java/org/onosproject/net/config/basics/BasicUiTopoLayoutConfigTest.java b/core/api/src/test/java/org/onosproject/net/config/basics/BasicUiTopoLayoutConfigTest.java
index f04dd9e..24b9031 100644
--- a/core/api/src/test/java/org/onosproject/net/config/basics/BasicUiTopoLayoutConfigTest.java
+++ b/core/api/src/test/java/org/onosproject/net/config/basics/BasicUiTopoLayoutConfigTest.java
@@ -42,7 +42,7 @@
 
     private static final String LAYOUT_JSON = "configs.layouts.1.json";
 
-    private static final String L_DEFAULT = "_default_";
+    private static final String L_DEFAULT = "root";
     private static final String L1 = "l1";
     private static final String L2 = "l2";
     private static final String L3 = "l3";
diff --git a/core/api/src/test/resources/org/onosproject/net/config/basics/configs.layouts.1.json b/core/api/src/test/resources/org/onosproject/net/config/basics/configs.layouts.1.json
index 790693b..f2c49aa 100644
--- a/core/api/src/test/resources/org/onosproject/net/config/basics/configs.layouts.1.json
+++ b/core/api/src/test/resources/org/onosproject/net/config/basics/configs.layouts.1.json
@@ -1,6 +1,6 @@
 {
   "layouts": {
-    "_default_": {
+    "root": {
       "basic": {
         "geomap": "uk",
         "scale": 1.2,