diff --git a/test/common/shouldDo.test.js b/test/common/shouldDo.test.js
index 144a2663be..5f2fe4494f 100644
--- a/test/common/shouldDo.test.js
+++ b/test/common/shouldDo.test.js
@@ -322,6 +322,25 @@ describe('shouldDo', () => {
       }
     });
 
+    it('returns false and ignore malformed repeat object', () => {
+      dailyTask.repeat = {
+        su: false,
+        s: false,
+        f: false,
+        th: false,
+        w: false,
+        t: false,
+        m: false,
+        errors: 'errors',
+      };
+
+      for (let weekday of [0, 1, 2, 3, 4, 5, 6]) {
+        day = moment().day(weekday).toDate();
+
+        expect(shouldDo(day, dailyTask, options)).to.equal(false);
+      }
+    });
+
     it('returns false if day of the week does not match and active on the day it matches', () => {
       dailyTask.repeat = {
         su: false,
diff --git a/website/common/script/cron.js b/website/common/script/cron.js
index bd6532278d..1205e15472 100644
--- a/website/common/script/cron.js
+++ b/website/common/script/cron.js
@@ -113,6 +113,7 @@ export function shouldDo (day, dailyTask, options = {}) {
 
   if (dailyTask.repeat) {
     for (let [repeatDay, active] of Object.entries(dailyTask.repeat)) {
+      if (!isFinite(DAY_MAPPING_STRING_TO_NUMBER[repeatDay])) continue; // eslint-disable-line no-continue
       if (active) daysOfTheWeek.push(parseInt(DAY_MAPPING_STRING_TO_NUMBER[repeatDay], 10));
     }
   }