diff --git a/templates/blocks/block--page-title-block.html.twig b/templates/blocks/block--page-title-block.html.twig
index 14502a34ef1e06ca573d00c7de72b573f971c7b3..899a3054191df227925223116e29008b8a26c6a1 100644
--- a/templates/blocks/block--page-title-block.html.twig
+++ b/templates/blocks/block--page-title-block.html.twig
@@ -1,4 +1,4 @@
-{% if not show_title %}
+{% if show_title is not defined %}
   {% set show_title = TRUE %}
 {% endif %}