diff --git a/templates/404.html b/templates/404.html
index 80acd2c..3534470 100644
--- a/templates/404.html
+++ b/templates/404.html
@@ -1,4 +1,4 @@
-{% extends "theme.html" %}
+{% extends theme_base %}
 {% load i18n %}
 
 {% block title %} {% trans "Error: page not found" %} {% endblock %}
diff --git a/templates/500.html b/templates/500.html
index 7125aae..224bd86 100644
--- a/templates/500.html
+++ b/templates/500.html
@@ -1,4 +1,4 @@
-{% extends "theme.html" %}
+{% extends theme_base %}
 {% load i18n %}
 
 {% block title %} {% trans "Error: server error (500)" %} {% endblock %}