diff --git a/src/ferry_planner/static/index.js b/src/ferry_planner/static/index.js
index f81de48..4ec0bb8 100644
--- a/src/ferry_planner/static/index.js
+++ b/src/ferry_planner/static/index.js
@@ -896,8 +896,9 @@ function onPlanSelected(id) {
 export function sortPlans(sortBy) {
   if (sortBy === currentSort) return;
   plans.sort((a, b) => {
-    if (a[sortBy] >= b[sortBy]) return 1;
-    return -1;
+    if (a[sortBy] > b[sortBy]) return 1;
+    if (a[sortBy] < b[sortBy]) return -1;
+    return 0;
   });
   currentSort = sortBy;
   elements.sortOption.value = sortBy;