diff --git a/templates/base.html b/templates/base.html
index 0da863e..bfed206 100644
--- a/templates/base.html
+++ b/templates/base.html
@@ -1,7 +1,9 @@
-{% if 'jinja2.ext.i18n' not in JINJA_ENVIRONMENT.extensions and 'jinja2.ext.i18n' not in JINJA_EXTENSIONS %}
- {%- macro _(msg) -%}
- {{ msg % kwargs }}
- {%- endmacro -%}
+{% if 'jinja2.ext.i18n' not in JINJA_ENVIRONMENT.extensions %}
+ {% if JINJA_EXTENSIONS is not defined or 'jinja2.ext.i18n' not in JINJA_EXTENSIONS %}
+ {%- macro _(msg) -%}
+ {{ msg % kwargs }}
+ {%- endmacro -%}
+ {% endif %}
{% endif %}