diff --git a/src/tools/annotation/CircleRoiTool.js b/src/tools/annotation/CircleRoiTool.js
index <HASH>..<HASH> 100644
--- a/src/tools/annotation/CircleRoiTool.js
+++ b/src/tools/annotation/CircleRoiTool.js
@@ -34,17 +34,13 @@ const logger = getLogger('tools:annotation:EllipticalRoiTool');
  * @extends Tools.Base.BaseAnnotationTool
  */
 export default class CircleRoiTool extends BaseAnnotationTool {
-  constructor(configuration = {}) {
-    const defaultConfig = {
+  constructor(props = {}) {
+    const defaultProps = {
       name: 'CircleRoi',
       supportedInteractionTypes: ['Mouse', 'Touch'],
     };
 
-    const initialConfiguration = Object.assign(defaultConfig, configuration);
-
-    super(initialConfiguration);
-
-    this.initialConfiguration = initialConfiguration;
+    super(props, defaultProps);
   }
 
   createNewMeasurement(eventData) {
fix(mergeConfig): Applying merge config fix into CircleRoiTool