diff --git a/src/AbstractOptions.php b/src/AbstractOptions.php
index 86e69c3d5..c58ea9ad1 100644
--- a/src/AbstractOptions.php
+++ b/src/AbstractOptions.php
@@ -65,7 +65,7 @@ public function setFromArray($options)
     public function toArray()
     {
         $array = array();
-        $transform = function($letters) {
+        $transform = function ($letters) {
             $letter = array_shift($letters);
             return '_' . strtolower($letter);
         };
diff --git a/src/Hydrator/ArraySerializable.php b/src/Hydrator/ArraySerializable.php
index 3b6cb18e2..2f2ba88d2 100644
--- a/src/Hydrator/ArraySerializable.php
+++ b/src/Hydrator/ArraySerializable.php
@@ -39,7 +39,7 @@ public function extract($object)
 
         $self = $this;
         $data = $object->getArrayCopy();
-        array_walk($data, function(&$value, $name) use ($self) {
+        array_walk($data, function (&$value, $name) use ($self) {
             $value = $self->extractValue($name, $value);
         });
         return $data;
@@ -59,7 +59,7 @@ public function extract($object)
     public function hydrate(array $data, $object)
     {
         $self = $this;
-        array_walk($data, function(&$value, $name) use ($self) {
+        array_walk($data, function (&$value, $name) use ($self) {
             $value = $self->hydrateValue($name, $value);
         });
 
diff --git a/src/Hydrator/ClassMethods.php b/src/Hydrator/ClassMethods.php
index 1ce91f0f1..26ffde175 100644
--- a/src/Hydrator/ClassMethods.php
+++ b/src/Hydrator/ClassMethods.php
@@ -52,7 +52,7 @@ public function extract($object)
             ));
         }
 
-        $transform = function($letters) {
+        $transform = function ($letters) {
             $letter = array_shift($letters);
             return '_' . strtolower($letter);
         };
@@ -97,7 +97,7 @@ public function hydrate(array $data, $object)
             ));
         }
 
-        $transform = function($letters) {
+        $transform = function ($letters) {
             $letter = substr(array_shift($letters), 1, 1);
             return ucfirst($letter);
         };
diff --git a/src/Hydrator/ObjectProperty.php b/src/Hydrator/ObjectProperty.php
index 2416de8a5..f2b0fa136 100644
--- a/src/Hydrator/ObjectProperty.php
+++ b/src/Hydrator/ObjectProperty.php
@@ -38,7 +38,7 @@ public function extract($object)
 
         $self = $this;
         $data = get_object_vars($object);
-        array_walk($data, function(&$value, $name) use ($self) {
+        array_walk($data, function (&$value, $name) use ($self) {
             $value = $self->extractValue($name, $value);
         });
         return $data;
diff --git a/src/PriorityQueue.php b/src/PriorityQueue.php
index ecb8fbd31..4b124bdcd 100644
--- a/src/PriorityQueue.php
+++ b/src/PriorityQueue.php
@@ -211,12 +211,12 @@ public function toArray($flag = self::EXTR_DATA)
                 return $this->items;
                 break;
             case self::EXTR_PRIORITY:
-                return array_map(function($item) {
+                return array_map(function ($item) {
                     return $item['priority'];
                 }, $this->items);
             case self::EXTR_DATA:
             default:
-                return array_map(function($item) {
+                return array_map(function ($item) {
                     return $item['data'];
                 }, $this->items);
         }