diff --git a/src/Entity/Project.php b/src/Entity/Project.php
index beb603f0..cf7050c9 100644
--- a/src/Entity/Project.php
+++ b/src/Entity/Project.php
@@ -257,6 +257,9 @@ class Project implements EntityWithMetaFields, EntityWithBudget
      *
      * @var bool
      *
+     * @Serializer\Expose()
+     * @Serializer\Groups({"Default"})
+     *
      * @ORM\Column(name="global_activities", type="boolean", nullable=false, options={"default": true})
      * @Assert\NotNull()
      */
diff --git a/src/Form/API/ProjectApiEditForm.php b/src/Form/API/ProjectApiEditForm.php
index d3a941f7..22ab4c64 100644
--- a/src/Form/API/ProjectApiEditForm.php
+++ b/src/Form/API/ProjectApiEditForm.php
@@ -10,6 +10,7 @@
 namespace App\Form\API;
 
 use App\Form\ProjectEditForm;
+use App\Form\Type\APITrueFalseType;
 use Symfony\Component\Form\FormBuilderInterface;
 use Symfony\Component\OptionsResolver\OptionsResolver;
 
@@ -23,6 +24,11 @@ class ProjectApiEditForm extends ProjectEditForm
         parent::buildForm($builder, $options);
 
         $builder->remove('metaFields');
+        $builder->remove('globalActivities');
+        $builder->add('globalActivities', APITrueFalseType::class, [
+            'label' => 'label.globalActivities',
+            'empty_data' => '1',
+        ]);
     }
 
     /**
diff --git a/src/Form/Type/APITrueFalseType.php b/src/Form/Type/APITrueFalseType.php
new file mode 100644
index 00000000..83001db0
--- /dev/null
+++ b/src/Form/Type/APITrueFalseType.php
@@ -0,0 +1,30 @@
+<?php
+
+/*
+ * This file is part of the Kimai time-tracking app.
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace App\Form\Type;
+
+use Symfony\Component\Form\AbstractType;
+use Symfony\Component\Form\Extension\Core\Type\CheckboxType;
+use Symfony\Component\OptionsResolver\OptionsResolver;
+
+class APITrueFalseType extends AbstractType
+{
+    public function configureOptions(OptionsResolver $resolver): void
+    {
+        $resolver->setDefaults([
+            'false_values' => [0, '0', false],
+            'required' => false,
+        ]);
+    }
+
+    public function getParent(): string
+    {
+        return CheckboxType::class;
+    }
+}
diff --git a/tests/API/APIControllerBaseTest.php b/tests/API/APIControllerBaseTest.php
index 7751f7de..8b07606e 100644
--- a/tests/API/APIControllerBaseTest.php
+++ b/tests/API/APIControllerBaseTest.php
@@ -433,6 +433,7 @@ abstract class APIControllerBaseTest extends ControllerBaseTest
                     'billable' => 'bool',
                     'color' => '@string',
                     'customer' => 'int',
+                    'globalActivities' => 'bool',
                     'comment' => '@string',
                 ];
 
@@ -445,6 +446,7 @@ abstract class APIControllerBaseTest extends ControllerBaseTest
                     'billable' => 'bool',
                     'color' => '@string',
                     'customer' => ['result' => 'object', 'type' => 'Customer'],
+                    'globalActivities' => 'bool',
                     'comment' => '@string',
                 ];
 
@@ -461,6 +463,7 @@ abstract class APIControllerBaseTest extends ControllerBaseTest
                     'parentTitle' => 'string',
                     'start' => '@datetime',
                     'end' => '@datetime',
+                    'globalActivities' => 'bool',
                     'teams' => ['result' => 'array', 'type' => 'Team'],
                     'comment' => '@string',
                 ];
@@ -478,6 +481,7 @@ abstract class APIControllerBaseTest extends ControllerBaseTest
                     'parentTitle' => 'string',
                     'start' => '@datetime',
                     'end' => '@datetime',
+                    'globalActivities' => 'bool',
                     'teams' => ['result' => 'array', 'type' => 'Team'],
                     'comment' => '@string',
                     'budget' => 'float',
diff --git a/tests/API/ProjectControllerTest.php b/tests/API/ProjectControllerTest.php
index 2d1d5c00..e224837e 100644
--- a/tests/API/ProjectControllerTest.php
+++ b/tests/API/ProjectControllerTest.php
@@ -298,12 +298,51 @@ class ProjectControllerTest extends APIControllerBaseTest
         $this->assertIsArray($result);
         self::assertApiResponseTypeStructure('ProjectEntity', $result);
         $this->assertNotEmpty($result['id']);
+        self::assertTrue($result['globalActivities']);
         self::assertEquals('2018-02-08T13:02:54+0000', $result['orderDate']);
         self::assertEquals('2019-02-01T19:32:17+0000', $result['start']);
         self::assertEquals('2020-02-08T21:11:42+0000', $result['end']);
         self::assertEquals('1234567890/WXYZ/SUBPROJECT/1234/CONTRACT/EMPLOYEE1', $result['orderNumber']);
     }
 
+    public function testPostActionWithOtherFields()
+    {
+        $client = $this->getClientForAuthenticatedUser(User::ROLE_ADMIN);
+        $data = [
+            'name' => 'foo',
+            'customer' => 1,
+            'globalActivities' => '0',
+        ];
+        $this->request($client, '/api/projects', 'POST', [], json_encode($data));
+        $this->assertTrue($client->getResponse()->isSuccessful());
+
+        $result = json_decode($client->getResponse()->getContent(), true);
+        $this->assertIsArray($result);
+        self::assertApiResponseTypeStructure('ProjectEntity', $result);
+        $this->assertNotEmpty($result['id']);
+        self::assertEquals('foo', $result['name']);
+        self::assertFalse($result['globalActivities']);
+    }
+
+    public function testPostActionWithOtherFields2()
+    {
+        $client = $this->getClientForAuthenticatedUser(User::ROLE_ADMIN);
+        $data = [
+            'name' => 'foo',
+            'customer' => 1,
+            'globalActivities' => '1',
+        ];
+        $this->request($client, '/api/projects', 'POST', [], json_encode($data));
+        $this->assertTrue($client->getResponse()->isSuccessful());
+
+        $result = json_decode($client->getResponse()->getContent(), true);
+        $this->assertIsArray($result);
+        self::assertApiResponseTypeStructure('ProjectEntity', $result);
+        $this->assertNotEmpty($result['id']);
+        self::assertEquals('foo', $result['name']);
+        self::assertTrue($result['globalActivities']);
+    }
+
     public function testPostActionWithLeastFields()
     {
         $client = $this->getClientForAuthenticatedUser(User::ROLE_ADMIN);