diff --git a/packages/vuetify/src/components/VSparkline/VTrendline.tsx b/packages/vuetify/src/components/VSparkline/VTrendline.tsx
index 4cee7027c04..62ee2ac6e1d 100644
--- a/packages/vuetify/src/components/VSparkline/VTrendline.tsx
+++ b/packages/vuetify/src/components/VSparkline/VTrendline.tsx
@@ -151,7 +151,7 @@ export const VTrendline = genericComponent<VTrendlineSlots>()({
     function genPath (fill: boolean) {
       return _genPath(
         genPoints(items.value, boundary.value),
-        props.smooth ? 8 : Number(props.smooth),
+        typeof props.smooth === 'number' ? props.smooth : props.smooth ? 8 : 0,
         fill,
         parseInt(props.height, 10)
       )
diff --git a/packages/vuetify/src/components/VSparkline/util/line.ts b/packages/vuetify/src/components/VSparkline/util/line.ts
index 04c6e264bbc..ad511f6b0c9 100644
--- a/packages/vuetify/src/components/VSparkline/util/line.ts
+++ b/packages/vuetify/src/components/VSparkline/util/line.ts
@@ -4,7 +4,7 @@ import { propsFactory } from '@/util'
 // Types
 import type { PropType } from 'vue'
 
-export type SparklineItem = number | { value: number }
+export type SparklineItem = string | number | { value: number }
 
 export const makeLineProps = propsFactory({
   autoDraw: Boolean,
@@ -55,7 +55,7 @@ export const makeLineProps = propsFactory({
     default: 8,
   },
   showLabels: Boolean,
-  smooth: Boolean,
+  smooth: [Boolean, Number],
   width: {
     type: [Number, String],
     default: 300,