diff --git a/lib/Varien/Data/Form/Element/Collection.php b/lib/Varien/Data/Form/Element/Collection.php
index 25d4ec55033..8c6e7bcf76c 100644
--- a/lib/Varien/Data/Form/Element/Collection.php
+++ b/lib/Varien/Data/Form/Element/Collection.php
@@ -58,7 +58,7 @@ public function __construct($container)
      *
      * @return ArrayIterator
      */
-    public function getIterator()
+    public function getIterator(): \Traversable
     {
         return new ArrayIterator($this->_elements);
     }
@@ -69,7 +69,7 @@ public function getIterator()
      * @param mixed $key
      * @param mixed $value
      */
-    public function offsetSet($key, $value)
+    public function offsetSet($key, $value): void
     {
         $this->_elements[$key] = $value;
     }
@@ -80,7 +80,7 @@ public function offsetSet($key, $value)
      * @param mixed $key
      * @return mixed
      */
-    public function offsetGet($key)
+    public function offsetGet($key): mixed
     {
         return $this->_elements[$key];
     }
@@ -90,7 +90,7 @@ public function offsetGet($key)
      *
      * @param mixed $key
      */
-    public function offsetUnset($key)
+    public function offsetUnset($key): void
     {
         unset($this->_elements[$key]);
     }
@@ -99,9 +99,9 @@ public function offsetUnset($key)
      * Implementation of ArrayAccess:offsetExists()
      *
      * @param mixed $key
-     * @return boolean
+     * @return bool
      */
-    public function offsetExists($key)
+    public function offsetExists($key): bool
     {
         return isset($this->_elements[$key]);
     }
@@ -179,7 +179,7 @@ public function remove($elementId)
      *
      * @return int
      */
-    public function count()
+    public function count(): int
     {
         return count($this->_elements);
     }
diff --git a/lib/Varien/Data/Tree/Node/Collection.php b/lib/Varien/Data/Tree/Node/Collection.php
index be863c3a856..084314167cb 100644
--- a/lib/Varien/Data/Tree/Node/Collection.php
+++ b/lib/Varien/Data/Tree/Node/Collection.php
@@ -59,7 +59,7 @@ public function getNodes()
     /**
     * Implementation of IteratorAggregate::getIterator()
     */
-    public function getIterator()
+    public function getIterator(): \Traversable
     {
         return new ArrayIterator($this->_nodes);
     }
@@ -69,7 +69,7 @@ public function getIterator()
      * @param string $key
      * @param string $value
      */
-    public function offsetSet($key, $value)
+    public function offsetSet($key, $value): void
     {
         $this->_nodes[$key] = $value;
     }
@@ -77,9 +77,9 @@ public function offsetSet($key, $value)
     /**
      * Implementation of ArrayAccess:offsetGet()
      * @param string $key
-     * @return Varien_Data_Tree_Node
+     * @return mixed|Varien_Data_Tree_Node
      */
-    public function offsetGet($key)
+    public function offsetGet($key): mixed
     {
         return $this->_nodes[$key];
     }
@@ -88,7 +88,7 @@ public function offsetGet($key)
      * Implementation of ArrayAccess:offsetUnset()
      * @param string $key
      */
-    public function offsetUnset($key)
+    public function offsetUnset($key): void
     {
         unset($this->_nodes[$key]);
     }
@@ -98,7 +98,7 @@ public function offsetUnset($key)
      * @param string $key
      * @return bool
      */
-    public function offsetExists($key)
+    public function offsetExists($key): bool
     {
         return isset($this->_nodes[$key]);
     }
@@ -139,7 +139,7 @@ public function delete($node)
      *
      * @return int
      */
-    public function count()
+    public function count(): int
     {
         return count($this->_nodes);
     }
diff --git a/lib/Varien/Db/Tree/NodeSet.php b/lib/Varien/Db/Tree/NodeSet.php
index 3e3619343be..a902bbd3de8 100644
--- a/lib/Varien/Db/Tree/NodeSet.php
+++ b/lib/Varien/Db/Tree/NodeSet.php
@@ -21,7 +21,6 @@
 
 /**
  * TODO implements iterators
- *
  */
 class Varien_Db_Tree_NodeSet implements Iterator
 {
@@ -60,31 +59,32 @@ public function count()
     /**
      * @return bool
      */
-    public function valid()
+    public function valid(): bool
     {
         return isset($this->_nodes[$this->_current]);
     }
 
+    #[\ReturnTypeWillChange]
     public function next()
     {
         if ($this->_current > $this->_currentNode) {
             return false;
         } else {
-            return  $this->_current++;
+            return $this->_current++;
         }
     }
 
-    public function key()
+    public function key(): mixed
     {
         return $this->_current;
     }
 
-    public function current()
+    public function current(): mixed
     {
         return $this->_nodes[$this->_current];
     }
 
-    public function rewind()
+    public function rewind(): void
     {
         $this->_current = 0;
     }
diff --git a/lib/Varien/Object.php b/lib/Varien/Object.php
index 790f897ef6d..46b374f379e 100644
--- a/lib/Varien/Object.php
+++ b/lib/Varien/Object.php
@@ -835,8 +835,7 @@ public function debug($data = null, &$objects = [])
      * @param string $offset
      * @param mixed $value
      */
-    #[ReturnTypeWillChange]
-    public function offsetSet($offset, $value)
+    public function offsetSet($offset, $value): void
     {
         $this->_data[$offset] = $value;
     }
@@ -846,10 +845,9 @@ public function offsetSet($offset, $value)
      *
      * @link http://www.php.net/manual/en/arrayaccess.offsetexists.php
      * @param string $offset
-     * @return boolean
+     * @return bool
      */
-    #[ReturnTypeWillChange]
-    public function offsetExists($offset)
+    public function offsetExists($offset): bool
     {
         return isset($this->_data[$offset]);
     }
@@ -860,8 +858,7 @@ public function offsetExists($offset)
      * @link http://www.php.net/manual/en/arrayaccess.offsetunset.php
      * @param string $offset
      */
-    #[ReturnTypeWillChange]
-    public function offsetUnset($offset)
+    public function offsetUnset($offset): void
     {
         unset($this->_data[$offset]);
     }
@@ -873,8 +870,7 @@ public function offsetUnset($offset)
      * @param string $offset
      * @return mixed
      */
-    #[ReturnTypeWillChange]
-    public function offsetGet($offset)
+    public function offsetGet($offset): mixed
     {
         return isset($this->_data[$offset]) ? $this->_data[$offset] : null;
     }