diff --git a/api/src/main/java/com/bartlomiejpluta/base/api/game/gui/GUI.java b/api/src/main/java/com/bartlomiejpluta/base/api/game/gui/GUI.java
new file mode 100644
index 00000000..0f03c76e
--- /dev/null
+++ b/api/src/main/java/com/bartlomiejpluta/base/api/game/gui/GUI.java
@@ -0,0 +1,7 @@
+package com.bartlomiejpluta.base.api.game.gui;
+
+import com.bartlomiejpluta.base.api.internal.logic.Updatable;
+import com.bartlomiejpluta.base.api.internal.render.Renderable;
+
+public interface GUI extends Updatable, Renderable {
+}
diff --git a/engine/src/main/java/com/bartlomiejpluta/base/engine/core/gl/render/DefaultRenderer.java b/engine/src/main/java/com/bartlomiejpluta/base/engine/core/gl/render/DefaultRenderer.java
index 57e1d1ab..f3d51c3d 100644
--- a/engine/src/main/java/com/bartlomiejpluta/base/engine/core/gl/render/DefaultRenderer.java
+++ b/engine/src/main/java/com/bartlomiejpluta/base/engine/core/gl/render/DefaultRenderer.java
@@ -22,15 +22,15 @@ public class DefaultRenderer implements Renderer {
    public void init() {
       log.info("Initializing renderer");
       shaderManager
-              .createShader("default", "/shaders/default.vs", "/shaders/default.fs")
-              .selectShader("default")
-              .createUniform(UniformName.UNI_VIEW_MODEL_MATRIX)
-              .createUniform(UniformName.UNI_PROJECTION_MATRIX)
-              .createUniform(UniformName.UNI_OBJECT_COLOR)
-              .createUniform(UniformName.UNI_HAS_OBJECT_TEXTURE)
-              .createUniform(UniformName.UNI_TEXTURE_SAMPLER)
-              .createUniform(UniformName.UNI_SPRITE_SIZE)
-              .createUniform(UniformName.UNI_SPRITE_POSITION);
+            .createShader("default", "/shaders/default.vs", "/shaders/default.fs")
+            .selectShader("default")
+            .createUniform(UniformName.UNI_VIEW_MODEL_MATRIX)
+            .createUniform(UniformName.UNI_PROJECTION_MATRIX)
+            .createUniform(UniformName.UNI_OBJECT_COLOR)
+            .createUniform(UniformName.UNI_HAS_OBJECT_TEXTURE)
+            .createUniform(UniformName.UNI_TEXTURE_SAMPLER)
+            .createUniform(UniformName.UNI_SPRITE_SIZE)
+            .createUniform(UniformName.UNI_SPRITE_POSITION);
    }
 
    @Override
@@ -51,7 +51,7 @@ public class DefaultRenderer implements Renderer {
    }
 
    private void clear() {
-      glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+      glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);
    }
 
    private void updateViewport(Screen screen) {
diff --git a/engine/src/main/java/com/bartlomiejpluta/base/engine/ui/GLFWScreen.java b/engine/src/main/java/com/bartlomiejpluta/base/engine/ui/GLFWScreen.java
index 83d064bc..4428b98e 100644
--- a/engine/src/main/java/com/bartlomiejpluta/base/engine/ui/GLFWScreen.java
+++ b/engine/src/main/java/com/bartlomiejpluta/base/engine/ui/GLFWScreen.java
@@ -97,6 +97,9 @@ public class GLFWScreen implements Screen {
       // Make the OpenGL context current
       glfwMakeContextCurrent(windowHandle);
 
+      // Enable antialiasing
+      glfwWindowHint(GLFW_SAMPLES, 4);
+
       // Enable V-Sync
       // glfwSwapInterval(1);
 
@@ -109,6 +112,9 @@ public class GLFWScreen implements Screen {
       glEnable(GL_BLEND);
       glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
 
+      // Required by GUI
+      glEnable(GL_STENCIL_TEST);
+
       // Set the clear color
       clear(0.0f, 0.0f, 0.0f, 0.0f);
    }