diff --git a/src/ScheduleMonitorServiceProvider.php b/src/ScheduleMonitorServiceProvider.php
index 8da0cd4..29fa3a1 100644
--- a/src/ScheduleMonitorServiceProvider.php
+++ b/src/ScheduleMonitorServiceProvider.php
@@ -5,6 +5,7 @@
 use Illuminate\Console\Events\CommandStarting;
 use Illuminate\Console\Scheduling\Event as SchedulerEvent;
 use Illuminate\Support\Facades\Event;
+use Laravel\Horizon\Horizon;
 use OhDear\PhpSdk\OhDear;
 use Spatie\LaravelPackageTools\Package;
 use Spatie\LaravelPackageTools\PackageServiceProvider;
@@ -88,6 +89,10 @@ protected function silenceOhDearJob(): self
             return $this;
         }
 
+        if (! class_exists(Horizon::class)) {
+            return $this;
+        }
+
         $silencedJobs = config('horizon.silenced', []);
 
         if (in_array(PingOhDearJob::class, $silencedJobs)) {