diff --git a/frontend/src/ts/ervu/component/grid/renderer/ValueWithPrefixRenderer.ts b/frontend/src/ts/ervu/component/grid/renderer/ValueWithPrefixRenderer.ts
index d96743b..294f9c5 100644
--- a/frontend/src/ts/ervu/component/grid/renderer/ValueWithPrefixRenderer.ts
+++ b/frontend/src/ts/ervu/component/grid/renderer/ValueWithPrefixRenderer.ts
@@ -13,6 +13,6 @@ export class ValueWithPrefixRenderer implements GridCellValueRenderer {
 
   render(params: ICellRendererParams): HTMLElement | string {
     let value = params.valueFormatted ? params.valueFormatted : params.value;
-    return `${this.label} ${value}`;
+    return value ? `${this.label} ${value}` : value;
   }
 }