diff --git a/src/AbstractContainerCommandLoader.php b/src/AbstractContainerCommandLoader.php
index 4891c92..f876b77 100644
--- a/src/AbstractContainerCommandLoader.php
+++ b/src/AbstractContainerCommandLoader.php
@@ -22,7 +22,7 @@ abstract class AbstractContainerCommandLoader implements CommandLoaderInterface
     private $commandMap;
 
     /** @psalm-param array<string, string> $commandMap */
-    final public function __construct(private ContainerInterface $container, array $commandMap)
+    final public function __construct(private readonly ContainerInterface $container, array $commandMap)
     {
         Assert::isMap($commandMap);
         Assert::allString($commandMap);
diff --git a/src/ContainerResolver.php b/src/ContainerResolver.php
index b7a2036..d3bf3a1 100644
--- a/src/ContainerResolver.php
+++ b/src/ContainerResolver.php
@@ -28,7 +28,7 @@ final class ContainerResolver
      * @psalm-param non-empty-string $projectRoot
      */
     public function __construct(
-        private string $projectRoot
+        private readonly string $projectRoot
     ) {
     }
 
diff --git a/src/Input/AbstractInputParam.php b/src/Input/AbstractInputParam.php
index 186d8c6..937e497 100644
--- a/src/Input/AbstractInputParam.php
+++ b/src/Input/AbstractInputParam.php
@@ -56,7 +56,7 @@ public function __construct(
         /**
          * Parameter name; must be set by class composing trait!
          */
-        private string $name
+        private readonly string $name
     ) {
     }
 
diff --git a/src/Input/AbstractParamAwareInput.php b/src/Input/AbstractParamAwareInput.php
index 4bdaf99..e53de72 100644
--- a/src/Input/AbstractParamAwareInput.php
+++ b/src/Input/AbstractParamAwareInput.php
@@ -5,6 +5,7 @@
 namespace Laminas\Cli\Input;
 
 use InvalidArgumentException;
+use Stringable;
 use Symfony\Component\Console\Helper\QuestionHelper;
 use Symfony\Component\Console\Input\InputDefinition;
 use Symfony\Component\Console\Input\InputInterface;
@@ -26,7 +27,7 @@
  *
  * @internal
  */
-abstract class AbstractParamAwareInput implements ParamAwareInputInterface
+abstract class AbstractParamAwareInput implements ParamAwareInputInterface, Stringable
 {
     /**
      * @param array<string, InputParamInterface> $params
diff --git a/src/Input/Mapper/ArrayInputMapper.php b/src/Input/Mapper/ArrayInputMapper.php
index f44f351..b4f9e5c 100644
--- a/src/Input/Mapper/ArrayInputMapper.php
+++ b/src/Input/Mapper/ArrayInputMapper.php
@@ -17,7 +17,7 @@ final class ArrayInputMapper implements InputMapperInterface
      * @psalm-param array<string|int, string|array<string, string>> $map
      */
     public function __construct(
-        private array $map
+        private readonly array $map
     ) {
     }
 
diff --git a/src/Listener/TerminateListener.php b/src/Listener/TerminateListener.php
index 414697e..3399bf2 100644
--- a/src/Listener/TerminateListener.php
+++ b/src/Listener/TerminateListener.php
@@ -18,11 +18,10 @@
 
 use function array_search;
 use function file_get_contents;
+use function get_debug_type;
 use function getcwd;
-use function gettype;
 use function is_array;
 use function is_int;
-use function is_object;
 use function is_string;
 use function json_decode;
 use function preg_match;
@@ -151,7 +150,7 @@ private function createInputMapper(mixed $inputMapperSpec, string $commandClass)
             'Expected array option map or %s class implementation name for %s input mapper; received "%s"',
             InputMapperInterface::class,
             $commandClass,
-            is_object($inputMapperSpec) ? $inputMapperSpec::class : gettype($inputMapperSpec)
+            get_debug_type($inputMapperSpec)
         ));
 
         Assert::classExists(