diff --git a/integrations/Symfony/Serializer/AvroSerDeEncoder.php b/integrations/Symfony/Serializer/AvroSerDeEncoder.php
index 14bbcc2..99d8013 100644
--- a/integrations/Symfony/Serializer/AvroSerDeEncoder.php
+++ b/integrations/Symfony/Serializer/AvroSerDeEncoder.php
@@ -51,7 +51,7 @@ public function supportsDecoding($format): bool
      * @throws \AvroSchemaParseException
      * @throws \FlixTech\SchemaRegistryApi\Exception\SchemaRegistryException
      */
-    public function encode($data, $format, array $context = [])
+    public function encode($data, $format, array $context = []): string
     {
         $this->validateEncodeContext($context);