diff --git a/app/Services/SimBriefService.php b/app/Services/SimBriefService.php
index 1d090533..f09880c5 100644
--- a/app/Services/SimBriefService.php
+++ b/app/Services/SimBriefService.php
@@ -192,11 +192,11 @@ class SimBriefService extends Service
     public function removeExpiredEntries(): void
     {
         $expire_days = setting('simbrief.expire_days', 5);
-        $expire_time = Carbon::now('UTC')->subDays($expire_days)->toDateTimeString();
+        $expire_time = Carbon::now('UTC')->subDays($expire_days);
 
         $briefs = SimBrief::where([
-            ['pirep_id', '=', ''],
-            ['created_at', '<', $expire_time],
+            ['pirep_id', null],
+            ['created_at', '<=', $expire_time],
         ])->get();
 
         foreach ($briefs as $brief) {
diff --git a/tests/SimBriefTest.php b/tests/SimBriefTest.php
index 0d00529f..a380396e 100644
--- a/tests/SimBriefTest.php
+++ b/tests/SimBriefTest.php
@@ -336,14 +336,13 @@ class SimBriefTest extends TestCase
             'user_id'    => $user->id,
             'flight_id'  => 'a_flight_id',
             'pirep_id'   => 'a_pirep_id',
-            'created_at' => Carbon::now('UTC')->subDays(6)->toDateTimeString(),
+            'created_at' => Carbon::now('UTC')->subDays(6),
         ]);
 
         factory(SimBrief::class)->create([
             'user_id'    => $user->id,
             'flight_id'  => 'a_flight_Id',
-            'pirep_id'   => '',
-            'created_at' => Carbon::now('UTC')->subDays(6)->toDateTimeString(),
+            'created_at' => Carbon::now('UTC')->subDays(6),
         ]);
 
         /** @var SimBriefService $sb */