diff --git a/src/CurlInfo.php b/src/CurlInfo.php
index 1cdaf19..ffac030 100644
--- a/src/CurlInfo.php
+++ b/src/CurlInfo.php
@@ -72,7 +72,7 @@ public function __get($prop)
      * The return value will be casted to boolean if non-boolean was returned.
      * @since 5.0.0
      */
-    public function offsetExists($offset)
+    public function offsetExists($offset): bool
     {
         return array_key_exists($offset, $this->info);
     }
@@ -86,6 +86,7 @@ public function offsetExists($offset)
      * @return mixed Can return all value types.
      * @since 5.0.0
      */
+    #[\ReturnTypeWillChange]
     public function offsetGet($offset)
     {
         return $this->info[$offset];
@@ -103,7 +104,7 @@ public function offsetGet($offset)
      * @return void
      * @since 5.0.0
      */
-    public function offsetSet($offset, $value)
+    public function offsetSet($offset, $value) : void
     {
         // READONLY
     }
@@ -117,7 +118,7 @@ public function offsetSet($offset, $value)
      * @return void
      * @since 5.0.0
      */
-    public function offsetUnset($offset)
+    public function offsetUnset($offset) : void
     {
         // READONLY
     }