diff --git a/composer.json b/composer.json
index 05d2eb8c..4d53f52f 100644
--- a/composer.json
+++ b/composer.json
@@ -27,6 +27,7 @@
     },
     "require": {
         "php": "^7.1",
+        "ext-json": "*",
         "monolog/monolog": "^1.23",
         "symfony/config": "^4.0",
         "symfony/filesystem": "^4.0",
diff --git a/src/Manifest/ManifestManager.php b/src/Manifest/ManifestManager.php
index 0d067fc1..23a52495 100644
--- a/src/Manifest/ManifestManager.php
+++ b/src/Manifest/ManifestManager.php
@@ -5,13 +5,12 @@
 namespace Keboola\Component\Manifest;
 
 use InvalidArgumentException;
+use Keboola\Component\JsonFileHelper;
 use Keboola\Component\Manifest\ManifestManager\Options\OutFileManifestOptions;
 use Keboola\Component\Manifest\ManifestManager\Options\OutTableManifestOptions;
 use Symfony\Component\Filesystem\Filesystem;
-use Symfony\Component\Serializer\Encoder\JsonEncoder;
-use const PATHINFO_EXTENSION;
-use function file_get_contents;
 use function pathinfo;
+use const PATHINFO_EXTENSION;
 
 /**
  * Handles everything related to generating and reading manifests for tables and files.
@@ -98,8 +97,7 @@ private function loadManifest(string $fileName, string $baseDir): array
             return [];
         }
 
-        $decoder = new JsonEncoder();
-        return $decoder->decode(file_get_contents($manifestFilename), JsonEncoder::FORMAT);
+        return JsonFileHelper::read($manifestFilename);
     }
 
     /**
@@ -108,10 +106,7 @@ private function loadManifest(string $fileName, string $baseDir): array
      */
     private function internalWriteManifest(string $manifestAbsolutePath, array $manifestContents): void
     {
-        $encoder = new JsonEncoder();
-        $manifestJson = $encoder->encode($manifestContents, JsonEncoder::FORMAT);
-        $filesystem = new Filesystem();
-        $filesystem->dumpFile($manifestAbsolutePath, $manifestJson . "\n");
+        JsonFileHelper::write($manifestAbsolutePath, $manifestContents, false);
     }
 
     /**