diff --git a/optuna_dashboard/ts/components/TrialTable.tsx b/optuna_dashboard/ts/components/TrialTable.tsx
index f3a55922..e88aebe6 100644
--- a/optuna_dashboard/ts/components/TrialTable.tsx
+++ b/optuna_dashboard/ts/components/TrialTable.tsx
@@ -160,7 +160,7 @@ export const TrialTable: FC<{
           if (firstVal === secondVal) {
             return 0
           } else if (firstVal && secondVal) {
-            return Number(firstVal) < Number(secondVal) ? 1 : -1
+            return firstVal < secondVal ? 1 : -1
           } else if (firstVal) {
             return -1
           } else {