diff --git a/examples/ExampleCommand.php b/examples/ExampleCommand.php
index f1d91f7..becb74a 100644
--- a/examples/ExampleCommand.php
+++ b/examples/ExampleCommand.php
@@ -23,7 +23,7 @@ protected function initialize(InputInterface $input, OutputInterface $output)
 	}
 
 	// Execute will be called in a endless loop
-	protected function execute(InputInterface $input, OutputInterface $output)
+	protected function execute(InputInterface $input, OutputInterface $output): int
 	{
 		// Tell the user what we're going to do.
 		// This will be silenced by Symfony if the user doesn't want any output at all,
@@ -52,6 +52,8 @@ protected function execute(InputInterface $input, OutputInterface $output)
 			// Tell the user we're done
 			$output->writeln('done');
 		}
+
+        return self::SUCCESS;
 	}
 
 	/**
@@ -59,14 +61,14 @@ protected function execute(InputInterface $input, OutputInterface $output)
 	 * @param InputInterface  $input
 	 * @param OutputInterface $output
 	 */
-	protected function finishIteration(InputInterface $input, OutputInterface $output)
+	protected function finishIteration(InputInterface $input, OutputInterface $output): void
 	{
 		// Do some cleanup/memory management here, don't forget to call the parent implementation!
 		parent::finishIteration($input, $output);
 	}
 
 	// Called once on shutdown after the last iteration finished
-	protected function finalize(InputInterface $input, OutputInterface $output)
+	protected function finalize(InputInterface $input, OutputInterface $output): void
 	{
 		// Do some cleanup here, don't forget to call the parent implementation!
 		parent::finalize($input, $output);
diff --git a/src/Wrep/Daemonizable/Command/EndlessCommand.php b/src/Wrep/Daemonizable/Command/EndlessCommand.php
index 6eca842..eecb51f 100644
--- a/src/Wrep/Daemonizable/Command/EndlessCommand.php
+++ b/src/Wrep/Daemonizable/Command/EndlessCommand.php
@@ -244,7 +244,7 @@ public function setCode(callable $code): static
      * @throws LogicException When this abstract method is not implemented
      * @see    setCode()
      */
-    protected function execute(InputInterface $input, OutputInterface $output)
+    protected function execute(InputInterface $input, OutputInterface $output): int
     {
         return parent::execute($input, $output);
     }
diff --git a/tests/Wrep/Daemonizable/Command/EndlessCommandTest.php b/tests/Wrep/Daemonizable/Command/EndlessCommandTest.php
index b829ab0..d91d3e4 100644
--- a/tests/Wrep/Daemonizable/Command/EndlessCommandTest.php
+++ b/tests/Wrep/Daemonizable/Command/EndlessCommandTest.php
@@ -110,8 +110,10 @@ public function testInterruptSigtermFromDifferentContext(): void
  */
 class EndlessSelfTerminatingCommand extends EndlessCommand
 {
-    protected function execute(InputInterface $input, OutputInterface $output)
+    protected function execute(InputInterface $input, OutputInterface $output): int
     {
         posix_kill(posix_getpid(), SIGTERM);
+
+        return self::SUCCESS;
     }
 }