diff --git a/application/Espo/Core/FileStorage/Manager.php b/application/Espo/Core/FileStorage/Manager.php
index a9bb2aab74..283bf42d0a 100644
--- a/application/Espo/Core/FileStorage/Manager.php
+++ b/application/Espo/Core/FileStorage/Manager.php
@@ -35,7 +35,7 @@ use Psr\Http\Message\StreamInterface;
 
 use RuntimeException;
 
-use function GuzzleHttp\Psr7\stream_for;
+use GuzzleHttp\Psr7\Utils;
 
 /**
  * An access point for file storing and fetching. Files are represented as Attachment entities.
@@ -119,7 +119,7 @@ class Manager
     {
         $implementation = $this->getImplementation($attachment);
 
-        $stream = stream_for($contents);
+        $stream = Utils::streamFor($contents);
 
         $implementation->putStream(self::wrapAttachmentEntity($attachment), $stream);
     }
diff --git a/application/Espo/Core/FileStorage/Storages/AwsS3.php b/application/Espo/Core/FileStorage/Storages/AwsS3.php
index a0c8045508..89144a6495 100644
--- a/application/Espo/Core/FileStorage/Storages/AwsS3.php
+++ b/application/Espo/Core/FileStorage/Storages/AwsS3.php
@@ -113,6 +113,8 @@ class AwsS3 implements Storage
             throw new RuntimeException("Could not open temp.");
         }
 
+        $stream->rewind();
+
         fwrite($resource, $stream->getContents());
         rewind($resource);
 
diff --git a/application/Espo/Core/FileStorage/Storages/EspoUploadDir.php b/application/Espo/Core/FileStorage/Storages/EspoUploadDir.php
index a2cb697bdd..efaf0321e1 100644
--- a/application/Espo/Core/FileStorage/Storages/EspoUploadDir.php
+++ b/application/Espo/Core/FileStorage/Storages/EspoUploadDir.php
@@ -99,6 +99,9 @@ class EspoUploadDir implements Storage, Local
     {
         $filePath = $this->getFilePath($attachment);
 
+        $stream->rewind();
+
+        // @todo Use a resource to write a file (add a method to the file manager).
         $contents = $stream->getContents();
 
         $result = $this->fileManager->putContents($filePath, $contents);