diff --git a/11/tutorial-11.lisp b/11-clip-rendering-and-sprite-sheets.lisp
similarity index 55%
rename from 11/tutorial-11.lisp
rename to 11-clip-rendering-and-sprite-sheets.lisp
index d4ff3f8..79e4d43 100644
--- a/11/tutorial-11.lisp
+++ b/11-clip-rendering-and-sprite-sheets.lisp
@@ -1,8 +1,9 @@
-(defpackage #:sdl2-tutorial-11
-  (:use :common-lisp)
-  (:export :main))
+(defpackage #:sdl2-tutorial-11-clip-rendering-and-sprite-sheets
+  (:use :cl)
+  (:export :run)
+  (:import-from :sdl2-tutorial-utils :asset-pathname))
 
-(in-package :sdl2-tutorial-11)
+(in-package :sdl2-tutorial-11-clip-rendering-and-sprite-sheets)
 
 (defparameter *screen-width* 640)
 (defparameter *screen-height* 480)
@@ -21,15 +22,16 @@
     :accessor tex-texture
     :initform nil)))
 
-(defun load-texture-from-file (renderer filename)
+(defun load-texture-from-file (renderer pathname)
   (let ((tex (make-instance 'tex :renderer renderer)))
     (with-slots (renderer texture  width height) tex
-      (let ((surface (sdl2-image:load-image filename)))
+      (let ((surface (sdl2-image:load-image pathname)))
         (setf width (sdl2:surface-width surface))
         (setf height (sdl2:surface-height surface))
         (sdl2:set-color-key surface :true (sdl2:map-rgb (sdl2:surface-format surface)
                                                         0 #xFF #xFF))
-        (setf texture (sdl2:create-texture-from-surface renderer surface))))
+        (setf texture (sdl2:create-texture-from-surface renderer surface))
+        (sdl2:free-surface surface)))
     tex))
 
 (defun render (tex x y &key clip)
@@ -45,46 +47,45 @@
 (defmacro with-window-renderer ((window renderer) &body body)
   `(sdl2:with-init (:video)
      (sdl2:with-window (,window
-                        :title "SDL2 Tutorial"
+                        :title "SDL2 Tutorial 11"
                         :w *screen-width*
                         :h *screen-height*
                         :flags '(:shown))
        (sdl2:with-renderer (,renderer ,window :index -1 :flags '(:accelerated))
          ,@body))))
 
-(defun main()
+(defun run ()
   (with-window-renderer (window renderer)
     (sdl2-image:init '(:png))
-    (let ((spritesheet-tex (load-texture-from-file renderer "11/spritesheet.png"))
-          (sprite-clips '(:top-left (0 0 100 100)
-                          :top-right (100 0 100 100)
-                          :bottom-left (0 100 100 100)
-                          :bottom-right (100 100 100 100))))
+    (let ((spritesheet-tex (load-texture-from-file renderer (asset-pathname #P"assets/11/spritesheet.png")))
+          (top-left (sdl2:make-rect 0 0 100 100))
+          (top-right (sdl2:make-rect 100 0 100 100))
+          (bottom-left (sdl2:make-rect 0 100 100 100))
+          (bottom-right (sdl2:make-rect 100 100 100 100)))
       (sdl2:with-event-loop (:method :poll)
         (:quit () t)
         (:idle ()
                (sdl2:set-render-draw-color renderer #xFF #xFF #xFF #xFF)
                (sdl2:render-clear renderer)
 
-               (let ((rect (apply #'sdl2::make-rect (getf sprite-clips :top-left))))
-                 (render spritesheet-tex 0 0 :clip rect))
+               (render spritesheet-tex
+                       0
+                       0
+                       :clip top-left)
 
-               (let ((rect (apply #'sdl2::make-rect (getf sprite-clips :top-right))))
-                 (render spritesheet-tex
-                         (- *screen-width* (sdl2:rect-width rect))
-                         0
-                         :clip rect))
+               (render spritesheet-tex
+                       (- *screen-width* (sdl2:rect-width top-right))
+                       0
+                       :clip top-right)
 
-               (let ((rect (apply #'sdl2::make-rect (getf sprite-clips :bottom-left))))
-                 (render spritesheet-tex
-                         0
-                         (- *screen-height* (sdl2:rect-height rect))
-                         :clip rect))
+               (render spritesheet-tex
+                       0
+                       (- *screen-height* (sdl2:rect-height bottom-left))
+                       :clip bottom-left)
 
-               (let ((rect (apply #'sdl2::make-rect (getf sprite-clips :bottom-right))))
-                 (render spritesheet-tex
-                         (- *screen-width* (sdl2:rect-width rect))
-                         (- *screen-height* (sdl2:rect-height rect))
-                         :clip rect))
+               (render spritesheet-tex
+                       (- *screen-width* (sdl2:rect-width bottom-right))
+                       (- *screen-height* (sdl2:rect-height bottom-right))
+                       :clip bottom-right)
 
                (sdl2:render-present renderer))))))
diff --git a/11/spritesheet.png b/assets/11/spritesheet.png
similarity index 100%
rename from 11/spritesheet.png
rename to assets/11/spritesheet.png
diff --git a/sdl2-tutorial.asd b/sdl2-tutorial.asd
index 7f6e217..ccf7e90 100644
--- a/sdl2-tutorial.asd
+++ b/sdl2-tutorial.asd
@@ -15,7 +15,7 @@
                (:file "08-geometry-rendering")
                (:file "09-the-viewport")
                (:file "10-color-keying")
-               (:file "11/tutorial-11")
+               (:file "11-clip-rendering-and-sprite-sheets")
                (:file "12/tutorial-12")
                (:file "13/tutorial-13")
                (:file "14/tutorial-14")