diff --git a/src/Config.php b/src/Config.php
index 80ce31b..54996b7 100644
--- a/src/Config.php
+++ b/src/Config.php
@@ -30,7 +30,7 @@ class Config implements Countable, Iterator, ArrayAccess
     /**
      * Whether modifications to configuration data are allowed.
      *
-     * @var boolean
+     * @var bool
      */
     protected $allowModifications;
 
@@ -52,7 +52,7 @@ class Config implements Countable, Iterator, ArrayAccess
      * Used when unsetting values during iteration to ensure we do not skip
      * the next element.
      *
-     * @var boolean
+     * @var bool
      */
     protected $skipNextIteration;
 
@@ -63,11 +63,11 @@ class Config implements Countable, Iterator, ArrayAccess
      * on construction.
      *
      * @param  array   $array
-     * @param  boolean $allowModifications
+     * @param  bool $allowModifications
      */
     public function __construct(array $array, $allowModifications = false)
     {
-        $this->allowModifications = (boolean) $allowModifications;
+        $this->allowModifications = (bool) $allowModifications;
 
         foreach ($array as $key => $value) {
             if (is_array($value)) {
@@ -185,7 +185,7 @@ public function toArray()
      * isset() overloading
      *
      * @param  string $name
-     * @return boolean
+     * @return bool
      */
     public function __isset($name)
     {
@@ -276,7 +276,7 @@ public function rewind()
      * valid(): defined by Iterator interface.
      *
      * @see    Iterator::valid()
-     * @return boolean
+     * @return bool
      */
     public function valid()
     {
@@ -288,7 +288,7 @@ public function valid()
      *
      * @see    ArrayAccess::offsetExists()
      * @param  mixed $offset
-     * @return boolean
+     * @return bool
      */
     public function offsetExists($offset)
     {
@@ -396,7 +396,7 @@ public function setReadOnly()
     /**
      * Returns whether this Config object is read only or not.
      *
-     * @return boolean
+     * @return bool
      */
     public function isReadOnly()
     {
diff --git a/src/Factory.php b/src/Factory.php
index a495be9..825f071 100644
--- a/src/Factory.php
+++ b/src/Factory.php
@@ -43,7 +43,7 @@ class Factory
      * Read a config from a file.
      *
      * @param  string  $filename
-     * @param  boolean $returnConfigObject
+     * @param  bool $returnConfigObject
      * @return array|Config
      * @throws Exception\InvalidArgumentException
      * @throws Exception\RuntimeException
@@ -93,7 +93,7 @@ public static function fromFile($filename, $returnConfigObject = false)
      * Read configuration from multiple files and merge them.
      *
      * @param  array   $files
-     * @param  boolean $returnConfigObject
+     * @param  bool $returnConfigObject
      * @return array|Config
      */
     public static function fromFiles(array $files, $returnConfigObject = false)
diff --git a/src/Reader/ReaderInterface.php b/src/Reader/ReaderInterface.php
index a99410d..55d76a9 100644
--- a/src/Reader/ReaderInterface.php
+++ b/src/Reader/ReaderInterface.php
@@ -29,7 +29,7 @@ public function fromFile($filename);
      * Read from a string and create an array
      *
      * @param  string $string
-     * @return array|boolean
+     * @return array|bool
      */
     public function fromString($string);
 }
diff --git a/src/Writer/AbstractWriter.php b/src/Writer/AbstractWriter.php
index f9d48b7..5d59f8a 100644
--- a/src/Writer/AbstractWriter.php
+++ b/src/Writer/AbstractWriter.php
@@ -28,7 +28,7 @@ abstract class AbstractWriter implements WriterInterface
      * @see    WriterInterface::toFile()
      * @param  string  $filename
      * @param  mixed   $config
-     * @param  boolean $exclusiveLock
+     * @param  bool $exclusiveLock
      * @return void
      * @throws Exception\InvalidArgumentException
      * @throws Exception\RuntimeException
diff --git a/src/Writer/Ini.php b/src/Writer/Ini.php
index f6822d3..a516f11 100644
--- a/src/Writer/Ini.php
+++ b/src/Writer/Ini.php
@@ -74,7 +74,7 @@ public function setRenderWithoutSectionsFlags($withoutSections)
     /**
      * Return whether the writer should render without sections.
      *
-     * @return boolean
+     * @return bool
      */
     public function shouldRenderWithoutSections()
     {
diff --git a/src/Writer/WriterInterface.php b/src/Writer/WriterInterface.php
index ea3894a..755d3dd 100644
--- a/src/Writer/WriterInterface.php
+++ b/src/Writer/WriterInterface.php
@@ -22,7 +22,7 @@ interface WriterInterface
      *
      * @param  string  $filename
      * @param  mixed   $config
-     * @param  boolean $exclusiveLock
+     * @param  bool $exclusiveLock
      * @return void
      */
     public function toFile($filename, $config, $exclusiveLock = true);