diff --git a/scripts/_common.sh b/scripts/_common.sh
index 173b14b..c66e49f 100644
--- a/scripts/_common.sh
+++ b/scripts/_common.sh
@@ -1,5 +1,12 @@
 #!/bin/bash
 
+#=================================================
+# COMMON VARIABLES
+#=================================================
+
+# dependencies used by the app
+pkg_dependencies="git build-essential libxslt-dev python-dev python-virtualenv python-cffi virtualenv python-babel zlib1g-dev libffi-dev libssl-dev python-lxml uwsgi uwsgi-plugin-python"
+
 #=================================================
 # FUTURE OFFICIAL HELPERS
 #=================================================
diff --git a/scripts/install b/scripts/install
index ac1924e..7d0fd1c 100644
--- a/scripts/install
+++ b/scripts/install
@@ -59,7 +59,7 @@ ynh_app_setting_set $app is_public $is_public
 #=================================================
 ynh_print_info "Installing dependencies..."
 
-ynh_install_app_dependencies git build-essential libxslt-dev python-dev python-virtualenv virtualenv python-babel zlib1g-dev libffi-dev libssl-dev python-lxml uwsgi uwsgi-plugin-python
+ynh_install_app_dependencies $pkg_dependencies
 
 #=================================================
 # NGINX CONFIGURATION
diff --git a/scripts/restore b/scripts/restore
index 881bbae..ca9171b 100755
--- a/scripts/restore
+++ b/scripts/restore
@@ -60,7 +60,7 @@ ynh_restore_file "$final_path"
 #=================================================
 ynh_print_info "Reinstalling dependencies..."
 
-ynh_install_app_dependencies git build-essential libxslt-dev python-dev python-virtualenv virtualenv python-babel zlib1g-dev libffi-dev libssl-dev python-lxml uwsgi uwsgi-plugin-python
+ynh_install_app_dependencies $pkg_dependencies
 
 #=================================================
 # RECREATE OF THE DEDICATED USER
diff --git a/scripts/upgrade b/scripts/upgrade
index ac4bdac..4c67861 100644
--- a/scripts/upgrade
+++ b/scripts/upgrade
@@ -69,7 +69,7 @@ path_url=$(ynh_normalize_url_path $path_url)
 #=================================================
 ynh_print_info "Upgrading dependencies..."
 
-ynh_install_app_dependencies git build-essential libxslt-dev python-dev python-virtualenv virtualenv python-babel zlib1g-dev libffi-dev libssl-dev python-lxml uwsgi uwsgi-plugin-python
+ynh_install_app_dependencies $pkg_dependencies
 
 #=================================================
 # DOWNLOAD, CHECK AND UNPACK SOURCE
diff --git a/sources/extra_files/app/requirements-ynh.txt b/sources/extra_files/app/requirements-ynh.txt
index d0a8eef..eb02727 100644
--- a/sources/extra_files/app/requirements-ynh.txt
+++ b/sources/extra_files/app/requirements-ynh.txt
@@ -13,6 +13,6 @@ requests[socks]==2.18.4
 # Additionnals requirements
 markupsafe>=0.23
 ndg-httpsclient>=0.4.2
-pyasn1>=0.1.9
-pyasn1-modules>=0.0.8
-cffi>=1.6
+pyasn1>=0.2.3
+pyasn1-modules>=0.0.9
+cffi>=1.12.1