diff --git a/.github/workflows/integration.yml b/.github/workflows/integration.yml
index 95e6783d2..d53f5ccd5 100644
--- a/.github/workflows/integration.yml
+++ b/.github/workflows/integration.yml
@@ -72,7 +72,7 @@ jobs:
         with:
           php-version: ${{ matrix.php-versions }}
           tools: phpunit
-          extensions: mbstring, iconv, fileinfo, intl, sqlite, pdo_sqlite, mysql, pdo_mysql, pgsql, pdo_pgsql,
+          extensions: mbstring, gd, iconv, fileinfo, intl, sqlite, pdo_sqlite, mysql, pdo_mysql, pgsql, pdo_pgsql,
           coverage: none
 
       - name: Set up PHPUnit
diff --git a/.github/workflows/phpunit.yml b/.github/workflows/phpunit.yml
index 48c5ee220..04cda0056 100644
--- a/.github/workflows/phpunit.yml
+++ b/.github/workflows/phpunit.yml
@@ -62,7 +62,7 @@ jobs:
           path: apps/${{ env.APP_NAME }}
 
       - name: Set up php ${{ matrix.php-versions }}
-        uses: shivammathur/setup-php@2.18.0
+        uses: shivammathur/setup-php@2.15.0
         with:
           php-version: ${{ matrix.php-versions }}
           tools: phpunit
diff --git a/lib/Service/ConfigService.php b/lib/Service/ConfigService.php
index 5aca2222c..48bf068c0 100644
--- a/lib/Service/ConfigService.php
+++ b/lib/Service/ConfigService.php
@@ -176,4 +176,12 @@ class ConfigService {
 
 		return $this->config->getUserValue($userId ?? $this->getUserId(), 'deck', 'attachment_folder', '/Deck');
 	}
+
+	public function setAttachmentFolder(?string $userId = null, string $path): void {
+		if ($userId === null && $this->getUserId() === null) {
+			throw new NoPermissionException('Must be logged in get the attachment folder');
+		}
+
+		$this->config->setUserValue($userId ?? $this->getUserId(), 'deck', 'attachment_folder', $path);
+	}
 }
diff --git a/lib/Service/FilesAppService.php b/lib/Service/FilesAppService.php
index 2ec7de929..e214b7ca3 100644
--- a/lib/Service/FilesAppService.php
+++ b/lib/Service/FilesAppService.php
@@ -31,6 +31,7 @@ use OCA\Deck\Sharing\DeckShareProvider;
 use OCA\Deck\StatusException;
 use OCP\AppFramework\Http\StreamResponse;
 use OCP\Constants;
+use OCP\Files\Folder;
 use OCP\Files\IMimeTypeDetector;
 use OCP\Files\IRootFolder;
 use OCP\Files\NotFoundException;
@@ -189,6 +190,16 @@ class FilesAppService implements IAttachmentService, ICustomAttachmentService {
 			$folder = $userFolder->newFolder($this->configService->getAttachmentFolder());
 		}
 
+		if ($folder->isShared()) {
+			$folderName = $userFolder->getNonExistingName($this->configService->getAttachmentFolder());
+			$folder = $userFolder->newFolder($folderName);
+			$this->configService->setAttachmentFolder($this->userId, $folderName);
+		}
+
+		if (!$folder instanceof Folder || $folder->isShared()) {
+			throw new NotFoundException('No target folder found');
+		}
+
 		$fileName = $folder->getNonExistingName($fileName);
 		$target = $folder->newFile($fileName);
 		$content = fopen($file['tmp_name'], 'rb');