diff --git a/htdocs/ai/admin/setup.php b/htdocs/ai/admin/setup.php
index 7f460b9c3f2..a670bc5492c 100644
--- a/htdocs/ai/admin/setup.php
+++ b/htdocs/ai/admin/setup.php
@@ -72,6 +72,7 @@ $arrayofia = array(
 
 $item = $formSetup->newItem('AI_API_SERVICE');	// Name of constant must end with _KEY so it is encrypted when saved into database.
 $item->setAsSelect($arrayofia);
+$item->cssClass = 'minwidth150';
 
 foreach ($arrayofia as $ia => $ialabel) {
 	// Setup conf AI_PUBLIC_INTERFACE_TOPIC
diff --git a/htdocs/core/class/html.formsetup.class.php b/htdocs/core/class/html.formsetup.class.php
index 0e208be320f..54e2203b0b4 100644
--- a/htdocs/core/class/html.formsetup.class.php
+++ b/htdocs/core/class/html.formsetup.class.php
@@ -1106,7 +1106,7 @@ class FormSetupItem
 		if ($this->picto) {
 			$s .= img_picto('', $this->picto, 'class="pictofixedwidth"');
 		}
-		$s .= $this->form->selectarray($this->confKey, $this->fieldOptions, $this->fieldValue);
+		$s .= $this->form->selectarray($this->confKey, $this->fieldOptions, $this->fieldValue, 0, 0, 0, '', 0, 0, 0, '', $this->cssClass);
 
 		return $s;
 	}