diff --git a/source/Game.cpp b/source/Game.cpp
index 470dd6c..9aca64a 100644
--- a/source/Game.cpp
+++ b/source/Game.cpp
@@ -244,7 +244,7 @@ Game::render() {
 /**
  * Returns current FPS as string.
  */
-sf::String
+String
 Game::getFps() {
 	return str((mElapsed != 0) ? 1000.0f / mElapsed : 0.0f, 2);
 }
diff --git a/source/Game.h b/source/Game.h
index 155e503..5c7e971 100644
--- a/source/Game.h
+++ b/source/Game.h
@@ -19,6 +19,7 @@
 #include "TileManager.h"
 #include "sprite/Player.h"
 #include "util/Collection.h"
+#include "util/String.h"
 
 class Player;
 class Collection;
@@ -46,7 +47,7 @@ private:
 	void mouseUp(const sf::Event& event);
 
 	void generate();
-	sf::String getFps();
+	String getFps();
 	sf::Vector2<float> convertCoordinates(int x, int y);
 
 // Private variables.
diff --git a/source/TileManager.cpp b/source/TileManager.cpp
index 14a14bc..1a64e64 100755
--- a/source/TileManager.cpp
+++ b/source/TileManager.cpp
@@ -9,9 +9,10 @@
 
 #include <Thor/Resources.hpp>
 
+#include "abstract/Sprite.h"
 #include "util/Loader.h"
 #include "util/ResourceManager.h"
-#include "abstract/Sprite.h"
+#include "util/String.h"
 
 const Vector2i TileManager::TILE_SIZE = Vector2i(100, 100);
 
@@ -45,7 +46,7 @@ TileManager::Tile::Tile(Type type, const TilePosition& position, b2World& world)
  */
 std::shared_ptr<sf::Texture>
 TileManager::Tile::getTexture(Type type) {
-	sf::String filename;
+	String filename;
 	switch (type) {
 	case Type::FLOOR:
 		filename = "floor.png";
diff --git a/source/abstract/Character.cpp b/source/abstract/Character.cpp
index 29b0d6c..af8e951 100644
--- a/source/abstract/Character.cpp
+++ b/source/abstract/Character.cpp
@@ -17,7 +17,7 @@ std::vector<Character*> Character::mCharacterInstances = std::vector<Character*>
 /**
  * Saves pointer to this instance in static var for think().
  */
-Character::Character(const Instances& instances, const sf::String& texturePath,
+Character::Character(const Instances& instances, const String& texturePath,
 	const PhysicalData& data, int health) :
 		Sprite(texturePath, data),
 		mMaxHealth(health),
diff --git a/source/abstract/Character.h b/source/abstract/Character.h
index b0aa530..0c6ceca 100644
--- a/source/abstract/Character.h
+++ b/source/abstract/Character.h
@@ -12,6 +12,7 @@
 
 #include "Sprite.h"
 #include "../Instances.h"
+#include "../util/String.h"
 
 class Instances;
 class Sprite;
@@ -22,7 +23,7 @@ class Sprite;
 class Character : public Sprite {
 // Public functions.
 public:
-	Character(const Instances& instances, const sf::String& texturePath,
+	Character(const Instances& instances, const String& texturePath,
 		const PhysicalData& data, int health);
 	virtual ~Character() = 0;
 
diff --git a/source/abstract/Sprite.cpp b/source/abstract/Sprite.cpp
index 65e367b..de8e5ce 100644
--- a/source/abstract/Sprite.cpp
+++ b/source/abstract/Sprite.cpp
@@ -8,7 +8,6 @@
 #include "Sprite.h"
 
 #include "../util/Loader.h"
-#include "../util/String.h"
 #include "../util/ResourceManager.h"
 
 /**
@@ -16,7 +15,7 @@
  *
  * @param texturePath Relative path to the texture file in the resource folder.
  */
-Sprite::Sprite(const sf::String& texturePath, const PhysicalData& data) :
+Sprite::Sprite(const String& texturePath, const PhysicalData& data) :
 		Physical(data),
 		mTexture(ResourceManager::i().acquire(Loader::i().fromFile<sf::Texture>(texturePath))),
 		mSize(data.size) {
diff --git a/source/abstract/Sprite.h b/source/abstract/Sprite.h
index 8a8b486..c0b8f7d 100644
--- a/source/abstract/Sprite.h
+++ b/source/abstract/Sprite.h
@@ -14,6 +14,7 @@
 
 #include "Physical.h"
 #include "../util/Vector.h"
+#include "../util/String.h"
 
 class Physical;
 
@@ -25,7 +26,7 @@ class Physical;
 class Sprite : public sf::Drawable, public Physical {
 // Public functions.
 public:
-	Sprite(const sf::String& texturePath, const PhysicalData& data);
+	Sprite(const String& texturePath, const PhysicalData& data);
 	Sprite(const std::shared_ptr<sf::Texture>& texture, const PhysicalData& data);
 	virtual ~Sprite() = 0;
 
diff --git a/source/sprite/Player.cpp b/source/sprite/Player.cpp
index 0b64f41..2c95098 100644
--- a/source/sprite/Player.cpp
+++ b/source/sprite/Player.cpp
@@ -11,6 +11,7 @@
 
 #include "../util/Vector.h"
 #include "../items/Weapon.h"
+#include "../util/String.h"
 
 const float Player::SPEED = 100.0f;
 const Vector2i Player::SIZE = Vector2i(50, 50);
diff --git a/source/util/String.h b/source/util/String.h
index add34c3..ac1f136 100644
--- a/source/util/String.h
+++ b/source/util/String.h
@@ -12,10 +12,10 @@
 #ifndef DG_STRING_H_
 #define DG_STRING_H_
 
-#include <math.h>
 #include <sstream>
+#include <string>
 
-#include <SFML/System.hpp>
+typedef std::string String;
 
 /**
  * Converts any value to a string.
@@ -24,7 +24,7 @@
  * @return val converted to string.
  */
 template <typename T>
-sf::String
+String
 str(T val) {
 	std::stringstream out;
 	out << val;
@@ -39,7 +39,7 @@ str(T val) {
  * @return val converted to string.
  */
 template <typename T>
-sf::String
+String
 str(T val, int digits) {
 	std::stringstream out;
 	out.precision(digits);