diff --git a/packages/x-charts/src/ChartsGrid/ChartsHorizontalGrid.tsx b/packages/x-charts/src/ChartsGrid/ChartsHorizontalGrid.tsx
index 2827e782e4cd..04eb4164b956 100644
--- a/packages/x-charts/src/ChartsGrid/ChartsHorizontalGrid.tsx
+++ b/packages/x-charts/src/ChartsGrid/ChartsHorizontalGrid.tsx
@@ -23,9 +23,9 @@ export function ChartsGridHorizontal(props: ChartsGridHorizontalProps) {
 
   return (
     <React.Fragment>
-      {yTicks.map(({ formattedValue, offset }) => (
+      {yTicks.map(({ value, offset }) => (
         <GridLine
-          key={`horizontal-${formattedValue}`}
+          key={`horizontal-${value}`}
           y1={offset}
           y2={offset}
           x1={drawingArea.left}
diff --git a/packages/x-charts/src/ChartsGrid/ChartsVerticalGrid.tsx b/packages/x-charts/src/ChartsGrid/ChartsVerticalGrid.tsx
index b033d5c1b8ea..b8f9da31ca43 100644
--- a/packages/x-charts/src/ChartsGrid/ChartsVerticalGrid.tsx
+++ b/packages/x-charts/src/ChartsGrid/ChartsVerticalGrid.tsx
@@ -23,9 +23,9 @@ export function ChartsGridVertical(props: ChartsGridVerticalProps) {
 
   return (
     <React.Fragment>
-      {xTicks.map(({ formattedValue, offset }) => (
+      {xTicks.map(({ value, offset }) => (
         <GridLine
-          key={`vertical-${formattedValue}`}
+          key={`vertical-${value}`}
           y1={drawingArea.top}
           y2={drawingArea.top + drawingArea.height}
           x1={offset}