diff --git a/optuna_dashboard/ts/components/TrialTable.tsx b/optuna_dashboard/ts/components/TrialTable.tsx
index ed930c9c..8fcce63c 100644
--- a/optuna_dashboard/ts/components/TrialTable.tsx
+++ b/optuna_dashboard/ts/components/TrialTable.tsx
@@ -157,7 +157,7 @@ export const TrialTable: FC<{
         if (firstVal === secondVal) {
           return 0
         } else if (firstVal && secondVal) {
-          return firstVal < secondVal ? 1 : -1
+          return Number(firstVal) < Number(secondVal) ? 1 : -1
         } else if (firstVal) {
           return -1
         } else {