diff --git a/packages/cedar/CHANGELOG.md b/packages/cedar/CHANGELOG.md
index 7518e2b..a2c3d9b 100644
--- a/packages/cedar/CHANGELOG.md
+++ b/packages/cedar/CHANGELOG.md
@@ -5,6 +5,9 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 
 ## [Unreleased]
 
+### Fixed
+- fix constructor casts dataset authentication to a POJO
+
 ## [1.1.0]
 
 ### Added
diff --git a/packages/cedar/src/Chart.ts b/packages/cedar/src/Chart.ts
index b885809..0850eb6 100644
--- a/packages/cedar/src/Chart.ts
+++ b/packages/cedar/src/Chart.ts
@@ -3,10 +3,6 @@ import { IDataset, ISeries } from './common'
 import { getChartData } from './dataset'
 import { queryDatasets } from './query/query'
 
-function clone(json) {
-  return JSON.parse(JSON.stringify(json))
-}
-
 // TODO: where should these interfaces live?
 
 /**
@@ -114,7 +110,7 @@ export class Chart {
 
     if (definition) {
       // set the definition
-      this.definition(clone(definition))
+      this.definition(definition)
     }
   }