diff --git a/include/JGL/JGL.h b/include/JGL/JGL.h
index 712c5d0..d68a30c 100644
--- a/include/JGL/JGL.h
+++ b/include/JGL/JGL.h
@@ -34,8 +34,14 @@ namespace JGL {
         float value;
     };
 
-    Vector2 ScreenToViewport(const Vector2& v);
-    Vector2 ViewportToScreen(const Vector2& v);
+    Vector2 ScreenToViewport(const Vector2& v)
+    {
+        // TODO: Implement matrix transformation
+    }
+    Vector2 ViewportToScreen(const Vector2& v)
+    {
+        // TODO: Implement matrix transformation
+    }
 
     void DrawPixel2D(const Color3 &, int x, int y);
     void DrawPixel2D(const Color3& color, const Vector2 &coordinates);