diff --git a/scripts/install b/scripts/install
index a1e5086..fa65c51 100644
--- a/scripts/install
+++ b/scripts/install
@@ -7,6 +7,7 @@
 #=================================================
 
 source _common.sh
+source ynh_composer__2
 source /usr/share/yunohost/helpers
 
 #=================================================
@@ -102,17 +103,20 @@ ynh_add_fpm_config
 
 #=================================================
 # SPECIFIC SETUP
+#=================================================
+# INSTALL COMPOSER
+#=================================================
+ynh_print_info --message="Installing Composer..."
+
+ynh_install_composer
+
 #================================================
 # CONCRETE5 INSTALLATION
 #=================================================
 ynh_print_info --message="Concrete5 Installation, the installation can take long. So be patient ! :)"
 
 pushd $final_path
-        php -r "copy('https://getcomposer.org/installer', 'composer-setup.php');"
-        php composer-setup.php
-        php -r "unlink('composer-setup.php');"
-        php ./composer.phar install
-        sudo ./concrete/bin/concrete5 c5:install --db-server=localhost \
+        ./concrete/bin/concrete5 c5:install --db-server=localhost \
                                         --db-database=$db_name \
                                         --db-username=$db_name \
                                         --db-password=$db_pwd \
diff --git a/scripts/upgrade b/scripts/upgrade
index 15fe6e9..f07e4a7 100644
--- a/scripts/upgrade
+++ b/scripts/upgrade
@@ -7,6 +7,7 @@
 #=================================================
 
 source _common.sh
+source ynh_composer__2
 source /usr/share/yunohost/helpers
 
 #=================================================
@@ -118,9 +119,17 @@ ynh_add_fpm_config
 
 #=================================================
 # SPECIFIC UPGRADE
+#=================================================
+# UPGRADE COMPOSER
+#=================================================
+ynh_print_info --message="Upgrading Composer..."
+
+ynh_install_composer
+
 #=================================================
 # UPGRADE CONCRETE
 #=================================================
+ynh_print_info --message="Upgrading Concrete..."
 
 pushd $final_path
     sudo ./concrete/bin/concrete5 c5:update --rerun --verbose --allow-as-root
diff --git a/scripts/ynh_composer__2 b/scripts/ynh_composer__2
new file mode 100644
index 0000000..1b6aa80
--- /dev/null
+++ b/scripts/ynh_composer__2
@@ -0,0 +1,48 @@
+#!/bin/bash
+
+# Execute a command with Composer
+#
+# usage: ynh_composer_exec --phpversion=phpversion [--workdir=$final_path] --commands="commands"
+# | arg: -w, --workdir - The directory from where the command will be executed. Default $final_path.
+# | arg: -c, --commands - Commands to execute.
+ynh_composer_exec () {
+	# Declare an array to define the options of this helper.
+	local legacy_args=vwc
+	declare -Ar args_array=( [v]=phpversion= [w]=workdir= [c]=commands= )
+	local phpversion
+	local workdir
+	local commands
+	# Manage arguments with getopts
+	ynh_handle_getopts_args "$@"
+	workdir="${workdir:-$final_path}"
+	phpversion="${phpversion:-7.0}"
+
+	COMPOSER_HOME="$workdir/.composer" \
+		php${phpversion} "$workdir/composer.phar" $commands \
+		-d "$workdir" --quiet --no-interaction
+}
+
+# Install and initialize Composer in the given directory
+#
+# usage: ynh_install_composer --phpversion=phpversion [--workdir=$final_path]
+# | arg: -w, --workdir - The directory from where the command will be executed. Default $final_path.
+ynh_install_composer () {
+	# Declare an array to define the options of this helper.
+	local legacy_args=vw
+	declare -Ar args_array=( [v]=phpversion= [w]=workdir= )
+	local phpversion
+	local workdir
+	# Manage arguments with getopts
+	ynh_handle_getopts_args "$@"
+	workdir="${workdir:-$final_path}"
+	phpversion="${phpversion:-7.0}"
+
+	curl -sS https://getcomposer.org/installer \
+		| COMPOSER_HOME="$workdir/.composer" \
+		php${phpversion} -- --quiet --install-dir="$workdir" \
+		|| ynh_die "Unable to install Composer."
+
+	# update dependencies to create composer.lock
+	ynh_composer_exec --phpversion="${phpversion}" --workdir="$workdir" --commands="install --no-dev" \
+		|| ynh_die "Unable to update core dependencies with Composer."
+}