diff --git a/src/Infusionsoft/Api/Rest/RestModel.php b/src/Infusionsoft/Api/Rest/RestModel.php
index c5ca512..78696e8 100644
--- a/src/Infusionsoft/Api/Rest/RestModel.php
+++ b/src/Infusionsoft/Api/Rest/RestModel.php
@@ -571,6 +571,7 @@ public function toJson($options = 0)
      *
      * @return array
      */
+    #[\ReturnTypeWillChange]
     public function jsonSerialize()
     {
         return $this->toArray();
@@ -982,6 +983,7 @@ public function __set($key, $value)
      *
      * @return bool
      */
+    #[\ReturnTypeWillChange]
     public function offsetExists($offset)
     {
         return isset($this->$offset);
@@ -994,6 +996,7 @@ public function offsetExists($offset)
      *
      * @return mixed
      */
+    #[\ReturnTypeWillChange]
     public function offsetGet($offset)
     {
         return $this->$offset;
@@ -1007,6 +1010,7 @@ public function offsetGet($offset)
      *
      * @return void
      */
+    #[\ReturnTypeWillChange]
     public function offsetSet($offset, $value)
     {
         $this->$offset = $value;
@@ -1019,6 +1023,7 @@ public function offsetSet($offset, $value)
      *
      * @return void
      */
+    #[\ReturnTypeWillChange]
     public function offsetUnset($offset)
     {
         unset($this->$offset);
diff --git a/src/Infusionsoft/InfusionsoftCollection.php b/src/Infusionsoft/InfusionsoftCollection.php
index d24fe15..63f9524 100644
--- a/src/Infusionsoft/InfusionsoftCollection.php
+++ b/src/Infusionsoft/InfusionsoftCollection.php
@@ -112,6 +112,7 @@ public function toArray()
 	 *
 	 * @return array
 	 */
+	#[\ReturnTypeWillChange]
 	public function jsonSerialize()
 	{
 		return $this->toArray();
@@ -133,6 +134,7 @@ public function toJson($options = 0)
 	 *
 	 * @return int
 	 */
+	#[\ReturnTypeWillChange]
 	public function count()
 	{
 		return count($this->items);
@@ -144,6 +146,7 @@ public function count()
 	 * @param  mixed  $key
 	 * @return bool
 	 */
+	#[\ReturnTypeWillChange]
 	public function offsetExists($key)
 	{
 		return array_key_exists($key, $this->items);
@@ -155,6 +158,7 @@ public function offsetExists($key)
 	 * @param  mixed  $key
 	 * @return mixed
 	 */
+	#[\ReturnTypeWillChange]
 	public function offsetGet($key)
 	{
 		return $this->items[$key];
@@ -167,6 +171,7 @@ public function offsetGet($key)
 	 * @param  mixed  $value
 	 * @return void
 	 */
+	#[\ReturnTypeWillChange]
 	public function offsetSet($key, $value)
 	{
 		if (is_null($key)) {
@@ -182,6 +187,7 @@ public function offsetSet($key, $value)
 	 * @param  string  $key
 	 * @return void
 	 */
+	#[\ReturnTypeWillChange]
 	public function offsetUnset($key)
 	{
 		unset($this->items[$key]);
@@ -216,4 +222,4 @@ protected function getArrayableItems($items)
 		return (array) $items;
 	}
 
-}
\ No newline at end of file
+}