diff --git a/components/src/model/theme.ts b/components/src/model/theme.ts
index 553877f..80d0c41 100644
--- a/components/src/model/theme.ts
+++ b/components/src/model/theme.ts
@@ -29,6 +29,7 @@ export interface PersesChartsTheme {
   sparkline: {
     width: number;
     color: string;
+    areaOpacity: number;
   };
   /**
    * Theming for the container that wraps a chart.