diff --git a/phpseclib/Math/BigInteger.php b/phpseclib/Math/BigInteger.php
index 276d7af3..434b3cfa 100644
--- a/phpseclib/Math/BigInteger.php
+++ b/phpseclib/Math/BigInteger.php
@@ -405,6 +405,8 @@ class BigInteger implements \JsonSerializable
      * JSON Serialize
      *
      * Will be called, automatically, when json_encode() is called on a BigInteger object.
+     *
+     * @return array{hex: string, precision?: int]
      */
     #[\ReturnTypeWillChange]
     public function jsonSerialize(): array
diff --git a/phpseclib/Math/BigInteger/Engines/Engine.php b/phpseclib/Math/BigInteger/Engines/Engine.php
index 21f82921..813beeeb 100644
--- a/phpseclib/Math/BigInteger/Engines/Engine.php
+++ b/phpseclib/Math/BigInteger/Engines/Engine.php
@@ -363,6 +363,8 @@ abstract class Engine implements \JsonSerializable
      * JSON Serialize
      *
      * Will be called, automatically, when json_encode() is called on a BigInteger object.
+     *
+     * @return array{hex: string, precision?: int]
      */
     #[\ReturnTypeWillChange]
     public function jsonSerialize(): array
diff --git a/phpseclib/Math/Common/FiniteField/Integer.php b/phpseclib/Math/Common/FiniteField/Integer.php
index 207d6c0d..615a03e0 100644
--- a/phpseclib/Math/Common/FiniteField/Integer.php
+++ b/phpseclib/Math/Common/FiniteField/Integer.php
@@ -28,6 +28,8 @@ abstract class Integer implements \JsonSerializable
      *
      * PHP Serialize isn't supported because unserializing would require the factory be
      * serialized as well and that just sounds like too much
+     *
+     * @return array{hex: string}
      */
     #[\ReturnTypeWillChange]
     public function jsonSerialize(): array