diff --git a/src/Illuminate/Support/Collection.php b/src/Illuminate/Support/Collection.php
index 43895b2..d76d799 100644
--- a/src/Illuminate/Support/Collection.php
+++ b/src/Illuminate/Support/Collection.php
@@ -1198,6 +1198,7 @@ public function toArray()
      *
      * @return array
      */
+    #[\ReturnTypeWillChange]
     public function jsonSerialize()
     {
         return array_map(function ($value) {
@@ -1229,6 +1230,7 @@ public function toJson($options = 0)
      *
      * @return \ArrayIterator
      */
+    #[\ReturnTypeWillChange]
     public function getIterator()
     {
         return new ArrayIterator($this->items);
@@ -1250,6 +1252,7 @@ public function getCachingIterator($flags = CachingIterator::CALL_TOSTRING)
      *
      * @return int
      */
+    #[\ReturnTypeWillChange]
     public function count()
     {
         return count($this->items);
@@ -1271,6 +1274,7 @@ public function toBase()
      * @param  mixed  $key
      * @return bool
      */
+    #[\ReturnTypeWillChange]
     public function offsetExists($key)
     {
         return array_key_exists($key, $this->items);
@@ -1282,6 +1286,7 @@ public function offsetExists($key)
      * @param  mixed  $key
      * @return mixed
      */
+    #[\ReturnTypeWillChange]
     public function offsetGet($key)
     {
         return $this->items[$key];
@@ -1294,6 +1299,7 @@ public function offsetGet($key)
      * @param  mixed  $value
      * @return void
      */
+    #[\ReturnTypeWillChange]
     public function offsetSet($key, $value)
     {
         if (is_null($key)) {
@@ -1309,6 +1315,7 @@ public function offsetSet($key, $value)
      * @param  string  $key
      * @return void
      */
+    #[\ReturnTypeWillChange]
     public function offsetUnset($key)
     {
         unset($this->items[$key]);