diff --git a/check_process b/check_process
index d415ff8..4a13a33 100644
--- a/check_process
+++ b/check_process
@@ -4,6 +4,7 @@
 		domain="domain.tld"	(DOMAIN)
 		path="/path"	(PATH)
 		is_public=1 (PUBLIC|public=1|private=0)
+		theme="milligram" (THEME)
 		password="verysecretpassword" (PASSWORD)
 	; Checks
 		pkg_linter=1
diff --git a/conf/lstu.conf.template b/conf/lstu.conf.template
index 76d4a50..b3bc0ac 100644
--- a/conf/lstu.conf.template
+++ b/conf/lstu.conf.template
@@ -33,7 +33,7 @@
 
     # choose a theme. See the available themes in `themes` directory
     # optional, default is 'default'
-    theme         => 'default',
+    theme         => '__SELECTED_THEME__', # default or milligram
 
     # number of URLs to be displayed per page in /stats
     # optional, default is 10
diff --git a/manifest.json b/manifest.json
index 881f28d..0c603fd 100644
--- a/manifest.json
+++ b/manifest.json
@@ -51,6 +51,16 @@
 				"default": false
 			},
 			{
+				"name": "theme",
+				"type": "string",
+				"ask": {
+					"en": "Choose a theme",
+					"fr": "Choisissez un theme"
+				},
+				"choices": ["default","milligram"],
+				"default": "milligram"
+      },
+      {
 				"name": "password",
 				"type": "password",
 				"ask": {
diff --git a/scripts/install b/scripts/install
index 2e4d24c..1f4d075 100644
--- a/scripts/install
+++ b/scripts/install
@@ -27,6 +27,7 @@ ynh_abort_if_errors
 domain=$YNH_APP_ARG_DOMAIN
 path_url=$YNH_APP_ARG_PATH
 is_public=$YNH_APP_ARG_IS_PUBLIC
+theme=$YNH_APP_ARG_THEME
 password=$YNH_APP_ARG_PASSWORD
 
 app=$YNH_APP_INSTANCE_NAME
@@ -65,6 +66,7 @@ ynh_app_setting_set $app domain $domain
 ynh_app_setting_set $app is_public $is_public
 ynh_app_setting_set $app port $port
 ynh_app_setting_set $app path $path_url
+ynh_app_setting_set $app theme $theme
 hashed_password=$(echo -n $password | sha256sum | cut -d' ' -f1)
 ynh_app_setting_set $app hashed_password $hashed_password
 
@@ -122,6 +124,7 @@ ynh_replace_string "__PORT__" "$port" "${final_path}/lstu.conf"
 ynh_replace_string "__DB_NAME__" "$db_name"  "${final_path}/lstu.conf"
 ynh_replace_string "__DB_USER__" "$db_user"  "${final_path}/lstu.conf"
 ynh_replace_string "__DB_PWD__" "$db_pwd" "${final_path}/lstu.conf"
+ynh_replace_string "__SELECTED_THEME__" "$theme" "${final_path}/lstu.conf"
 ynh_replace_string "__PASSWORD_HASHED__" "$hashed_password" "${final_path}/lstu.conf"
 
 secret=$(ynh_string_random 24)
diff --git a/scripts/upgrade b/scripts/upgrade
index a6672d3..fed6f4f 100644
--- a/scripts/upgrade
+++ b/scripts/upgrade
@@ -35,6 +35,7 @@ secret=$(ynh_app_setting_get $app secret)
 db_name=$(ynh_app_setting_get $app db_name)
 db_user=$db_name
 db_pwd=$(ynh_app_setting_get $app psqlpwd)
+theme=$(ynh_app_setting_get $app theme)
 hashed_password=$(ynh_app_setting_get $app hashed_password)
 
 #=================================================
@@ -69,6 +70,11 @@ if [ -z "$db_pwd" ]; then
 	fi
 fi
 
+if [ -z "$theme" ]; then
+	theme="milligram"
+	ynh_app_setting_set $app theme $theme
+fi
+
 if [ -z "$hashed_password" ]; then
 	# Generate random password
 	password=$(openssl rand -hex 8)
@@ -112,6 +118,7 @@ ynh_replace_string "__PORT__" "$port" "${final_path}/lstu.conf"
 ynh_replace_string "__DB_NAME__" "$db_name"  "${final_path}/lstu.conf"
 ynh_replace_string "__DB_USER__" "$db_user"  "${final_path}/lstu.conf"
 ynh_replace_string "__DB_PWD__" "$db_pwd" "${final_path}/lstu.conf"
+ynh_replace_string "__SELECTED_THEME__" "$theme" "${final_path}/lstu.conf"
 ynh_replace_string "__PASSWORD_HASHED__" "$hashed_password" "${final_path}/lstu.conf"
 
 ynh_replace_string "__SECRET__" "$secret" "${final_path}/lstu.conf"