diff --git a/src/Activity/ActivityService.php b/src/Activity/ActivityService.php
index cfcf2bde..d4ff5cd8 100644
--- a/src/Activity/ActivityService.php
+++ b/src/Activity/ActivityService.php
@@ -104,6 +104,6 @@ class ActivityService
 
     public function findActivityByName(string $name, ?Project $project = null): ?Activity
     {
-        return $this->repository->findOneBy(['project' => $project, 'name' => $name]);
+        return $this->repository->findOneBy(['project' => $project->getId(), 'name' => $name]);
     }
 }
diff --git a/src/Command/ImportTimesheetCommand.php b/src/Command/ImportTimesheetCommand.php
index 63394219..7dc4d131 100644
--- a/src/Command/ImportTimesheetCommand.php
+++ b/src/Command/ImportTimesheetCommand.php
@@ -508,7 +508,7 @@ class ImportTimesheetCommand extends Command
     {
         $tmpActivity = null;
 
-        $tmpActivities = $this->activities->findBy(['project' => $project, 'name' => $activity]);
+        $tmpActivities = $this->activities->findBy(['project' => $project->getId(), 'name' => $activity]);
 
         if (\count($tmpActivities) === 0) {
             $tmpActivity = $this->activities->findOneBy(['project' => null, 'name' => $activity]);