diff --git a/src/x/xSequentialFill.ts b/src/x/xSequentialFill.ts
index 28725ca2..15f70242 100644
--- a/src/x/xSequentialFill.ts
+++ b/src/x/xSequentialFill.ts
@@ -24,7 +24,7 @@ export function xSequentialFill(
   input: NumberArray | undefined,
   options?: XSequentialFillOptions,
 ): NumberArray;
-export function xSequentialFill(options?: XSequentialFillOptions): NumberArray;
+export function xSequentialFill(options?: XSequentialFillOptions): number[];
 /**
  * Fill an array with sequential numbers
  *