diff --git a/classes/class-blocks.php b/classes/class-blocks.php
index 778a7be8..2a309f06 100644
--- a/classes/class-blocks.php
+++ b/classes/class-blocks.php
@@ -1594,11 +1594,11 @@ public function render_callback( $attributes, $content = null, $context = 'front
 				'class' => '',
 			);
 
-			if ( $attributes['blockUniqueClass'] ) {
+			if ( isset( $attributes['blockUniqueClass'] ) && $attributes['blockUniqueClass'] ) {
 				$array_atts['class'] .= $attributes['blockUniqueClass'];
 			}
 
-			if ( $attributes['align'] ) {
+			if ( isset( $attributes['align'] ) && $attributes['align'] ) {
 				$array_atts['class'] .= ' align' . $attributes['align'];
 			}