diff --git a/packages/victory-core/src/index.d.ts b/packages/victory-core/src/index.d.ts
index fa23e0cb2..c6abd0397 100644
--- a/packages/victory-core/src/index.d.ts
+++ b/packages/victory-core/src/index.d.ts
@@ -680,7 +680,10 @@ export interface TextSizeStyleInterface {
 }
 
 export namespace TextSize {
-  export function approximateTextSize(text: string, style: TextSizeStyleInterface): number;
+  export function approximateTextSize(
+    text: string,
+    style?: TextSizeStyleInterface
+  ): { width: number; height: number };
   export function convertLengthToPixels(length: string, fontSize: number): number;
 }