diff --git a/README.md b/README.md
index fd89609..82b97ff 100644
--- a/README.md
+++ b/README.md
@@ -407,7 +407,7 @@ Merge the contents of two or more objects or arrays together into the first one.
 
 ##### `\DDTools\ObjectTools::unfold($params)`
 
-Converts a multidimensional array/object into an one-dimensional one joining the keys with `'.'`.
+Converts a multidimensional array/object into an one-dimensional one joining the keys with `$params->keySeparator`.
 For example, it can be helpful while using placeholders like `[+size.width+]`.
 
 * `$params`
@@ -424,6 +424,11 @@ For example, it can be helpful while using placeholders like `[+size.width+]`.
 		* `arrayAssociative`
 	* **Required**
 	
+* `$params->keySeparator`
+	* Desctription: Separator between nested keys in the result object/array.
+	* Valid values: `string`
+	* Default value: `'.'`
+	
 * `$params->keyPrefix`
 	* Desctription: Prefix of the keys of an object/array (it's an internal varible, but can be used if required).
 	* Valid values: `string`
@@ -1072,6 +1077,31 @@ array (
 ```
 
 
+##### Use custom key separator
+
+```php
+var_export(\DDTools\ObjectTools::unfold([
+	'object' => [
+		'name' => 'Elon Musk',
+		'parents' => [
+			'mother' => 'Maye Musk',
+			'father' => 'Errol Musk'
+		]
+	],
+	'keySeparator' => '_'
+]));
+```
+
+Returns:
+
+```php
+stdClass::__set_state(array (
+	'name' => 'Elon Musk',
+	'parents_mother' => 'Maye Musk',
+	'parents_father' => 'Errol Musk'
+))
+
+
 #### `\DDTools\ObjectTools::isPropExists($params)`
 
 Checks if the object, class or array has a property / element using the same syntax.
diff --git a/src/ObjectTools/ObjectTools.php b/src/ObjectTools/ObjectTools.php
index dc8f730..38ec36c 100644
--- a/src/ObjectTools/ObjectTools.php
+++ b/src/ObjectTools/ObjectTools.php
@@ -364,7 +364,7 @@ public static function extend($params){
 	
 	/**
 	 * unfold
-	 * @version 1.0 (2021-11-16)
+	 * @version 1.1 (2021-11-17)
 	 * 
 	 * @see README.md
 	 * 
@@ -375,6 +375,7 @@ public static function unfold($params){
 			'objects' => [
 				//Defaults
 				(object) [
+					'keySeparator' => '.',
 					'keyPrefix' => '',
 					//The internal parameter, should not be used outside. Used only in child calls of recursion.
 					'isSourceObject' => null
@@ -419,7 +420,7 @@ public static function unfold($params){
 						'keyPrefix' =>
 							$params->keyPrefix .
 							$key .
-							'.'
+							$params->keySeparator
 						,
 						'isSourceObject' => $isSourceObject
 					])