diff --git a/module2/ressources/rr_org/init.el b/module2/ressources/rr_org/init.el
index 62d3b1601facdfd913ebf18a457fc2f070e54d4f..eb85ea4c21062b600496b2ece241799149663695 100644
--- a/module2/ressources/rr_org/init.el
+++ b/module2/ressources/rr_org/init.el
@@ -57,16 +57,21 @@
 		 '("melpa-stable" . "http://stable.melpa.org/packages/"))
 (add-to-list 'package-archives
 		 '("melpa" . "http://melpa.org/packages/"))
-(package-refresh-contents)
 (setq package-archive-priorities '(("gnu" . 100)
                                    ("melpa-stable" . 10)))
 
-(dolist (pkg '(ess
-               auctex
-               htmlize
-               exec-path-from-shell))
-  (when (not (package-installed-p pkg))
-    (package-install pkg)))
+(let* ((required-packages
+        '(ess
+          auctex
+          htmlize
+          exec-path-from-shell))
+       (missing-packages (remove-if #'package-installed-p required-packages)))
+  (when missing-packages
+    (message "Missing packages: %s" missing-packages)
+    (package-refresh-contents)
+    (dolist (pkg missing-packages)
+      (package-install pkg)
+      (message "Package %s has been installed" pkg))))
 
 (unless (memq system-type '(windows-nt ms-dos))
   (exec-path-from-shell-initialize)
diff --git a/module2/ressources/rr_org/init.org b/module2/ressources/rr_org/init.org
index ed908912351261b86bf1acca291e761feb851b7e..0df6ec78642646c9c8c25791b3cbb41f889966f6 100644
--- a/module2/ressources/rr_org/init.org
+++ b/module2/ressources/rr_org/init.org
@@ -80,18 +80,23 @@ document, simply =M-x org-babel-tangle=.
 		 '("melpa-stable" . "http://stable.melpa.org/packages/"))
 (add-to-list 'package-archives
 		 '("melpa" . "http://melpa.org/packages/"))
-(package-refresh-contents)
 (setq package-archive-priorities '(("gnu" . 100)
                                    ("melpa-stable" . 10)))
 #+END_SRC
-* Install missing packages
-#+begin_src emacs-lisp :tangle init.el
-(dolist (pkg '(ess
-               auctex
-               htmlize
-               exec-path-from-shell))
-  (when (not (package-installed-p pkg))
-    (package-install pkg)))
+* Install packages
+#+begin_src emacs-lisp :tangle init.el
+(let* ((required-packages
+        '(ess
+          auctex
+          htmlize
+          exec-path-from-shell))
+       (missing-packages (remove-if #'package-installed-p required-packages)))
+  (when missing-packages
+    (message "Missing packages: %s" missing-packages)
+    (package-refresh-contents)
+    (dolist (pkg missing-packages)
+      (package-install pkg)
+      (message "Package %s has been installed" pkg))))
 #+end_src
 * Import environment variables
 #+begin_src emacs-lisp :tangle init.el