diff --git a/src/MDConsole.php b/src/MDConsole.php
index bc30850..87e71da 100644
--- a/src/MDConsole.php
+++ b/src/MDConsole.php
@@ -4,6 +4,7 @@
  *
  * @author Joshua Ramon Enslin <joshua@museum-digital.de>
  */
+declare(strict_types = 1);
 
 /**
  * Interface for CLI outputs of museum-digital's dev and admin tools.
@@ -109,7 +110,7 @@ class MDConsole {
     final public static function setupCLI():void {
 
         $startTime = microtime(true);
-        register_shutdown_function(function($startTime):void {
+        register_shutdown_function(function($startTime) :void {
 
             $duration = microtime(true) - $startTime;
 
diff --git a/src/MDOutputHandler.php b/src/MDOutputHandler.php
index 8d0478c..adf1e8f 100644
--- a/src/MDOutputHandler.php
+++ b/src/MDOutputHandler.php
@@ -4,6 +4,7 @@
  *
  * @author Joshua Ramon Enslin <joshua@museum-digital.de>
  */
+declare(strict_types = 1);
 
 /**
  * Class for handling outputs and logs for museum-digital's background tools.