diff --git a/types/chart.js/index.d.ts b/types/chart.js/index.d.ts
index f4f4bda40d..049488f8db 100644
--- a/types/chart.js/index.d.ts
+++ b/types/chart.js/index.d.ts
@@ -159,6 +159,7 @@ declare namespace Chart {
     interface ChartOptions {
         responsive?: boolean;
         responsiveAnimationDuration?: number;
+        aspectRatio?: number;
         maintainAspectRatio?: boolean;
         events?: string[];
         onClick?(event?: MouseEvent, activeElements?: Array<{}>): any;