diff --git a/composer.json b/composer.json
index c1202ec..0ecbc70 100644
--- a/composer.json
+++ b/composer.json
@@ -3,7 +3,7 @@
     "description": "Util to convert number to Czech words for Nette Framework",
     "type": "library",
     "require": {
-        "nette/application": "^2.4"
+        "php": ">= 5.6"
     },
     "license": "MIT",
     "authors": [
diff --git a/nbproject/project.properties b/nbproject/project.properties
deleted file mode 100644
index 76f6f91..0000000
--- a/nbproject/project.properties
+++ /dev/null
@@ -1,7 +0,0 @@
-include.path=${php.global.include.path}
-php.version=PHP_56
-source.encoding=UTF-8
-src.dir=.
-tags.asp=false
-tags.short=false
-web.root=.
diff --git a/nbproject/project.xml b/nbproject/project.xml
deleted file mode 100644
index 2e853a4..0000000
--- a/nbproject/project.xml
+++ /dev/null
@@ -1,9 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project xmlns="http://www.netbeans.org/ns/project/1">
-    <type>org.netbeans.modules.php.project</type>
-    <configuration>
-        <data xmlns="http://www.netbeans.org/ns/php-project/1">
-            <name>Number2czech-words</name>
-        </data>
-    </configuration>
-</project>
diff --git a/src/Utils/CzechNumber2Words.php b/src/Utils/CzechNumber2Words.php
index 880da06..18d50b3 100644
--- a/src/Utils/CzechNumber2Words.php
+++ b/src/Utils/CzechNumber2Words.php
@@ -2,6 +2,8 @@
 
 namespace Webnazakazku\Utils;
 
+use InvalidArgumentException;
+
 class CzechNumber2Words
 {
 	
@@ -57,7 +59,7 @@ public static function number2Words($number, $units = null, $level = -1)
 		
 		if ($number <= 0 || $number > 999999) {
 			// overflow
-			throw new \Nette\Application\ApplicationException('Invalid number range - value must be between 0 and 999 999');
+			throw new InvalidArgumentException('Invalid number range - value must be between 0 and 999 999');
 		}
 
 		switch (true) {