diff --git a/src/services/account-browsing-simulation.ts b/src/services/account-browsing-simulation.ts
index 162eef4..cf4d69b 100644
--- a/src/services/account-browsing-simulation.ts
+++ b/src/services/account-browsing-simulation.ts
@@ -74,7 +74,9 @@ export class AccountBrowsingSimulationService {
       this.options.repository.setNextDueAt(this.options.accountId, nextDueAt, now);
       return { kind: 'scheduled', nextDueAt };
     }
-    if (!force && now < settings.nextDueAt) return { kind: 'idle', reason: 'Browsing simulation is not due' };
+    if (!force && settings.nextDueAt !== null && now < settings.nextDueAt) {
+      return { kind: 'idle', reason: 'Browsing simulation is not due' };
+    }
     if (!force && isQuietTime(new Date(now), settings)) {
       const nextDueAt = moveOutsideQuietHours(now, settings);
       this.options.repository.setNextDueAt(this.options.accountId, nextDueAt, now);