diff --git a/src/Rendering/Bs3FormRenderer.php b/src/Rendering/Bs3FormRenderer.php
index cbf3f93..8472d54 100644
--- a/src/Rendering/Bs3FormRenderer.php
+++ b/src/Rendering/Bs3FormRenderer.php
@@ -109,7 +109,7 @@ private function controlsInit()
 		$this->form->getElementPrototype()->addClass('form-horizontal');
 		foreach ($this->form->getControls() as $control) {
 			if ($control instanceof Controls\Button) {
-				$markAsPrimary = $control === $this->primaryButton || (!isset($this->primary) && empty($usedPrimary) && $control->parent instanceof Form);
+				$markAsPrimary = $control === $this->primaryButton || (!isset($this->primaryButton) && empty($usedPrimary) && $control->parent instanceof Form);
 				if ($markAsPrimary) {
 					$class = 'btn btn-primary';
 					$usedPrimary = TRUE;