diff --git a/scripts/install b/scripts/install
index 71de790..8b2be9e 100644
--- a/scripts/install
+++ b/scripts/install
@@ -173,7 +173,7 @@ ynh_system_user_create "$app" "$final_path"
 mkdir -p /var/log/$app
 chown -R $app:$app /var/log/$app
 
-chown -R $app: $final_path
+chown -R "$app":"$app" "$final_path"
 pushd $final_path
 ynh_use_nodejs
 sudo -u $app env PATH=$PATH:$nodejs_path npm install hoek@^4.2.1 --save
diff --git a/scripts/restore b/scripts/restore
index 1b0b634..283baa1 100644
--- a/scripts/restore
+++ b/scripts/restore
@@ -74,7 +74,7 @@ ynh_system_user_create "$app" "$final_path"
 #=================================================
 
 # Restore permissions on app files
-chown -R $app:$app $final_path
+chown -R "$app":"$app" "$final_path"
 
 mkdir -p /var/log/$app
 chown -R $app:$app /var/log/$app
diff --git a/scripts/upgrade b/scripts/upgrade
index 2b6606f..2559edd 100644
--- a/scripts/upgrade
+++ b/scripts/upgrade
@@ -116,7 +116,7 @@ ynh_system_user_create "$app" "$final_path"
 # ...
 #=================================================
 
-chown -R $app: $final_path
+chown -R "$app":"$app" "$final_path"
 
 pushd $final_path
 ynh_use_nodejs