diff --git a/.gitignore b/.gitignore
index aad7e04..f068801 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,7 +1,6 @@
 #
 
 test.php
-tool.bat
 tool.sh
 composer.lock
 composer.bak.json
diff --git a/composer.json b/composer.json
index 3a58d4d..3d76e15 100644
--- a/composer.json
+++ b/composer.json
@@ -2,7 +2,7 @@
     "name": "xeriab/konfig",
     "description": "Yet another simple configuration loader library.",
     "homepage": "http://xeriab.github.io/projects/konfig/",
-    "version": "0.1.9",
+    "version": "0.2.0",
     "license": "MIT",
     "type": "library",
     "keywords": [
@@ -33,9 +33,9 @@
         "source": "https://github.com/xeriab/konfig"
     },
     "suggest": {
-        "yosymfony/toml": "Required to use and support TOML",
-        "symfony/yaml": "Required to use and support YAML",
-        "nette/neon": "Required to use and support the NEON notation"
+        "yosymfony/toml": "~0.3.3",
+        "symfony/yaml": "~2.8.12",
+        "nette/neon": "~2.3.5"
     },
     "require": {
         "php": ">=5.4.0"
@@ -44,7 +44,7 @@
         "yosymfony/toml": "~0.3.3",
         "symfony/yaml": "~2.8.12",
         "nette/neon": "~2.3.5",
-        "phpunit/phpunit": "~4.8.27",
+        "phpunit/phpunit": ">=4.8 < 6.0",
         "scrutinizer/ocular": "~1.3.1",
         "squizlabs/php_codesniffer": "~3.0.0RC1"
     },
diff --git a/src/Arr.php b/src/Arr.php
index 557d4c2..0f07d27 100644
--- a/src/Arr.php
+++ b/src/Arr.php
@@ -27,7 +27,7 @@ final class Arr
      * @codeCoverageIgnore
      * @since 0.1.0
      */
-    public static function get(array $array, $key, string $default = null)
+    public static function get(array $array, $key, $default = null)
     {
         if (!is_array($array) && !$array instanceof \ArrayAccess) {
             throw new \InvalidArgumentException('First parameter must be an array or ArrayAccess object.');
@@ -70,7 +70,7 @@ public static function get(array $array, $key, string $default = null)
      * @codeCoverageIgnore
      * @since 0.1.0
      */
-    public static function set(array &$array, $key, string $value = null)
+    public static function set(array &$array, $key, $value = null)
     {
         if (is_null($key)) {
             $array = $value;
@@ -187,7 +187,7 @@ public static function mergeAssoc()
      * @codeCoverageIgnore
      * @since 0.1.0
      */
-    public static function delete(array &$array, string $key)
+    public static function delete(array &$array, $key)
     {
         if (is_null($key)) {
             return false;
@@ -232,7 +232,7 @@ public static function delete(array &$array, string $key)
      * @codeCoverageIgnore
      * @since 0.1.0
      */
-    public static function keys(array $array, int $maxDepth = INF, int $depth = 0, array $arraykeys = [])
+    public static function keys(array $array, $maxDepth = INF, $depth = 0, array $arraykeys = [])
     {
         if ($depth < $maxDepth) {
             $depth++;
@@ -252,12 +252,12 @@ public static function keys(array $array, int $maxDepth = INF, int $depth = 0, a
      * Get array keys recursively
      *
      * @param array $array The search array
-     * @param type $search The search value
+     * @param string $search The search value
      * @return array
      * @codeCoverageIgnore
      * @since 0.1.2
      */
-    public static function recursiveKeys(array $array, string $search = null)
+    public static function recursiveKeys(array $array, $search = null)
     {
         $return = (
             $search !== null ?
diff --git a/src/Exception/ParseException.php b/src/Exception/ParseException.php
index b23567e..397a7c1 100644
--- a/src/Exception/ParseException.php
+++ b/src/Exception/ParseException.php
@@ -33,7 +33,7 @@ public function __construct(array $error)
         $lineNo    = isset($error['line']) ? $error['line'] : __LINE__;
         $exception = isset($error['exception']) ? $error['exception'] : null;
         $snippet   = isset($error['snippet']) ? $error['snippet'] : null;
-        $previous  = isset($error['previous']) ? $error['previous'] : null;
+        // $previous  = isset($error['previous']) ? $error['previous'] : null;
 
         $this->parsedFile = $fileName;
         $this->parsedLine = $lineNo;