diff --git a/src/Handler/ArrayCollectionHandler.php b/src/Handler/ArrayCollectionHandler.php
index f0bd6b36d..9523d0901 100644
--- a/src/Handler/ArrayCollectionHandler.php
+++ b/src/Handler/ArrayCollectionHandler.php
@@ -27,7 +27,7 @@ public function __construct(bool $initializeExcluded = true)
     /**
      * {@inheritdoc}
      */
-    public static function getSubscribingMethods()
+    public static function getSubscribingMethods() : iterable
     {
         $methods = [];
         $formats = ['json', 'xml', 'yml'];
diff --git a/src/Handler/ConstraintViolationHandler.php b/src/Handler/ConstraintViolationHandler.php
index d46291eb9..fecb64e2c 100644
--- a/src/Handler/ConstraintViolationHandler.php
+++ b/src/Handler/ConstraintViolationHandler.php
@@ -16,7 +16,7 @@ final class ConstraintViolationHandler implements SubscribingHandlerInterface
     /**
      * {@inheritdoc}
      */
-    public static function getSubscribingMethods()
+    public static function getSubscribingMethods() : iterable
     {
         $methods = [];
         $formats = ['xml', 'json'];
diff --git a/src/Handler/DateHandler.php b/src/Handler/DateHandler.php
index 981d8e21e..d8d2ff95f 100644
--- a/src/Handler/DateHandler.php
+++ b/src/Handler/DateHandler.php
@@ -31,7 +31,7 @@ final class DateHandler implements SubscribingHandlerInterface
     /**
      * {@inheritdoc}
      */
-    public static function getSubscribingMethods()
+    public static function getSubscribingMethods() : iterable
     {
         $methods = [];
         $types = ['DateTime', 'DateTimeImmutable', 'DateInterval'];
diff --git a/src/Handler/FormErrorHandler.php b/src/Handler/FormErrorHandler.php
index 60a40a454..e35037f7e 100644
--- a/src/Handler/FormErrorHandler.php
+++ b/src/Handler/FormErrorHandler.php
@@ -28,7 +28,7 @@ final class FormErrorHandler implements SubscribingHandlerInterface
     /**
      * {@inheritdoc}
      */
-    public static function getSubscribingMethods()
+    public static function getSubscribingMethods() : iterable
     {
         $methods = [];
         foreach (['xml', 'json'] as $format) {
diff --git a/src/Handler/IteratorHandler.php b/src/Handler/IteratorHandler.php
index b0971f59d..a16141d9a 100644
--- a/src/Handler/IteratorHandler.php
+++ b/src/Handler/IteratorHandler.php
@@ -21,7 +21,7 @@ final class IteratorHandler implements SubscribingHandlerInterface
     /**
      * {@inheritdoc}
      */
-    public static function getSubscribingMethods()
+    public static function getSubscribingMethods() : iterable
     {
         $methods = [];
 
diff --git a/src/Handler/StdClassHandler.php b/src/Handler/StdClassHandler.php
index 2e4686a67..f73fd18cb 100644
--- a/src/Handler/StdClassHandler.php
+++ b/src/Handler/StdClassHandler.php
@@ -17,7 +17,7 @@ final class StdClassHandler implements SubscribingHandlerInterface
     /**
      * {@inheritdoc}
      */
-    public static function getSubscribingMethods()
+    public static function getSubscribingMethods() : iterable
     {
         $methods = [];
         $formats = ['json', 'xml', 'yml'];
diff --git a/src/Handler/SubscribingHandlerInterface.php b/src/Handler/SubscribingHandlerInterface.php
index 4c206bc5d..1a4083b4b 100644
--- a/src/Handler/SubscribingHandlerInterface.php
+++ b/src/Handler/SubscribingHandlerInterface.php
@@ -20,9 +20,7 @@ interface SubscribingHandlerInterface
      *
      * The direction and method keys can be omitted.
      *
-     * @return array
-     *
-     * @phpcsSuppress SlevomatCodingStandard.TypeHints.TypeHintDeclaration.MissingReturnTypeHint
+     * @return iterable<string, int|string>
      */
-    public static function getSubscribingMethods();
+    public static function getSubscribingMethods() : iterable;
 }
diff --git a/tests/Serializer/GraphNavigatorTest.php b/tests/Serializer/GraphNavigatorTest.php
index 33de10008..638caa6f0 100644
--- a/tests/Serializer/GraphNavigatorTest.php
+++ b/tests/Serializer/GraphNavigatorTest.php
@@ -209,7 +209,7 @@ class TestSubscribingHandler implements SubscribingHandlerInterface
 {
     public const FORMAT = 'foo';
 
-    public static function getSubscribingMethods()
+    public static function getSubscribingMethods() : iterable
     {
         return [
             [