diff --git a/mu-plugins/carhop-post-types-supports.php b/mu-plugins/carhop-post-types-supports.php
new file mode 100644
index 0000000..53ac215
--- /dev/null
+++ b/mu-plugins/carhop-post-types-supports.php
@@ -0,0 +1,26 @@
+<?php
+
+/**
+ * Bouton « Citer » dans le header d’article : opt-in par type de contenu.
+ * Les types non listés (ex. actualités) n’affichent pas le bouton.
+ *
+ * @see post_type_supports( $post_type, 'carhop-citations' ) dans post-header.php
+ */
+function carhop_register_citation_support_for_post_types()
+{
+	$types_with_citations = array(
+		'analyses-etudes',
+		'recherches',
+		'expositions',
+		'actualites',
+		'outils-pedagogiques',
+		'activites',
+	);
+
+	foreach ($types_with_citations as $post_type) {
+		if (post_type_exists($post_type)) {
+			add_post_type_support($post_type, 'carhop-citations');
+		}
+	}
+}
+add_action('init', 'carhop_register_citation_support_for_post_types', 11);