diff --git a/src/Convert.php b/src/Convert.php
index e49c431..f46d0c1 100644
--- a/src/Convert.php
+++ b/src/Convert.php
@@ -53,5 +53,7 @@ protected function execute(InputInterface $input, OutputInterface $output)
         } else {
             $output->writeln($markdownData, OutputInterface::OUTPUT_RAW);
         }
+
+        return 0;
     }
 }