diff --git a/.gitea/workflows/pull-request.yml b/.gitea/workflows/pull-request.yml
index c981a71..8ee6923 100644
--- a/.gitea/workflows/pull-request.yml
+++ b/.gitea/workflows/pull-request.yml
@@ -56,7 +56,10 @@ jobs:
         uses: shivammathur/setup-php@v2
         with:
           php-version: '8.4'
-          extensions: pdo, pdo_pgsql, intl, opcache, zip, mbstring, sodium
+          # gd requis par phpoffice/phpspreadsheet (export XLSX). Doit etre explicite :
+          # sinon `composer install` echoue sur la verification de plateforme des que
+          # le runner ne fournit pas l'extension par defaut (ext-gd manquante).
+          extensions: pdo, pdo_pgsql, intl, opcache, zip, mbstring, sodium, gd
           coverage: none
           tools: composer:v2