diff --git a/src/Mapper/BaseGroupedMapper.php b/src/Mapper/BaseGroupedMapper.php
index 1e9d3fcf6d..dc3c5f3d51 100644
--- a/src/Mapper/BaseGroupedMapper.php
+++ b/src/Mapper/BaseGroupedMapper.php
@@ -329,10 +329,16 @@ protected function addFieldToCurrentGroup($fieldName)
     protected function getCurrentGroupName()
     {
         if (!$this->currentGroup) {
-            $this->with($this->admin->getLabel(), [
-                'auto_created' => true,
-                'translation_domain' => $this->admin->getTranslationDomain(),
-            ]);
+            $label = $this->admin->getLabel();
+
+            if (null === $label) {
+                $this->with('default', ['auto_created' => true]);
+            } else {
+                $this->with($label, [
+                    'auto_created' => true,
+                    'translation_domain' => $this->admin->getTranslationDomain(),
+                ]);
+            }
         }
 
         return $this->currentGroup;
diff --git a/tests/Form/FormMapperTest.php b/tests/Form/FormMapperTest.php
index 4c47c8537a..1094470314 100644
--- a/tests/Form/FormMapperTest.php
+++ b/tests/Form/FormMapperTest.php
@@ -534,6 +534,8 @@ public function testAddOptionRole(): void
         $this->assertTrue($this->formMapper->has('bar'));
         $this->assertFalse($this->formMapper->has('quux'));
 
+        $this->formMapper->end(); // Close default
+
         $this->formMapper
             ->with('qux')
                 ->add('foobar', 'bar', [], ['role' => self::DEFAULT_GRANTED_ROLE])
diff --git a/tests/Show/ShowMapperTest.php b/tests/Show/ShowMapperTest.php
index cffbf599a0..333b82825f 100644
--- a/tests/Show/ShowMapperTest.php
+++ b/tests/Show/ShowMapperTest.php
@@ -533,6 +533,8 @@ public function testAddOptionRole(): void
         $this->assertTrue($this->showMapper->has('bar'));
         $this->assertFalse($this->showMapper->has('quux'));
 
+        $this->showMapper->end(); // Close default
+
         $this->showMapper
             ->with('qux')
                 ->add('foobar', 'bar', ['role' => self::DEFAULT_GRANTED_ROLE])