diff --git a/src/Monolog/Processor/ProcessorInterface.php b/src/Monolog/Processor/ProcessorInterface.php
index a044f1cd..ebe41fc2 100644
--- a/src/Monolog/Processor/ProcessorInterface.php
+++ b/src/Monolog/Processor/ProcessorInterface.php
@@ -23,5 +23,5 @@ interface ProcessorInterface
     /**
      * @return LogRecord The processed record
      */
-    public function __invoke(LogRecord $record): LogRecord;
+    public function __invoke(LogRecord $record);
 }