diff --git a/src/BitArray.php b/src/BitArray.php
index f70b8ed..89a030b 100644
--- a/src/BitArray.php
+++ b/src/BitArray.php
@@ -81,8 +81,7 @@ public function __construct($data, $bitLength)
      * @param int $offset
      * @return bool
      */
-    #[\ReturnTypeWillChange]
-    public function offsetExists($offset)
+    public function offsetExists($offset):bool
     {
         if (!is_int($offset)) {
             return false;
@@ -124,8 +123,7 @@ public function offsetGet($offset)
      * @throws RangeException
      * @return void
      */
-    #[\ReturnTypeWillChange]
-    public function offsetSet($offset, $value)
+    public function offsetSet($offset, $value):void
     {
         $this->isValidOffset($offset);
         $value = (bool) $value;
@@ -149,8 +147,7 @@ public function offsetSet($offset, $value)
      * @throws RangeException
      * @return void
      */
-    #[\ReturnTypeWillChange]
-    public function offsetUnset($offset)
+    public function offsetUnset($offset):void
     {
         $this->offsetSet($offset, false);
     }
@@ -160,8 +157,7 @@ public function offsetUnset($offset)
      *
      * @return int Returns the total length in bits of the array
      */
-    #[\ReturnTypeWillChange]
-    public function count()
+    public function count():int
     {
         return $this->length;
     }
@@ -210,8 +206,7 @@ private function finalBitPos($offset)
     /**
      * @return array
      */
-    #[\ReturnTypeWillChange]
-    public function jsonSerialize()
+    public function jsonSerialize():array
     {
         return [
             'len' => $this->length,
diff --git a/src/BloomFilter.php b/src/BloomFilter.php
index fb3761c..f0a4da2 100644
--- a/src/BloomFilter.php
+++ b/src/BloomFilter.php
@@ -114,8 +114,7 @@ public function exists($item)
     /**
      * @return array
      */
-    #[\ReturnTypeWillChange]
-    public function jsonSerialize()
+    public function jsonSerialize():array
     {
         return [
             'bit_array' => $this->ba,
diff --git a/src/HasherList.php b/src/HasherList.php
index 532c104..aac8bda 100644
--- a/src/HasherList.php
+++ b/src/HasherList.php
@@ -89,8 +89,7 @@ public function hash($value)
     /**
      * @return array
      */
-    #[\ReturnTypeWillChange]
-    public function jsonSerialize()
+    public function jsonSerialize():array
     {
         return [
             'algo' => $this->algo,